Max Tennyson's History
Background
Magister Maxwell "Max" Tennyson or Grandpa Max as his grandchildren call him, is the paternal grandfather of Ben and Gwen. He is a fairly overweight man in his late 50's to early 60's, with a keen sense for adventure and a strange taste in food. Max ends up taking the kids on a summer vacations' road trip across the United States. Max travels in a motor home nicknamed the Rust Bucket, which he has modified with advanced technology.
Max was a semi-retired legendary Magister rank Plumber and is the mentor of Ben, Gwen, Kevin, and the Plumbers' Helpers. Max is widely considered the greatest Plumber in the Milky Way. As of Omniverse, Max quit retirement and joined the Plumbers again, and is currently Magister of Earth.
Not many details are provided on Max's childhood and background. In Permanent Retirement, Max's sister, Vera Tennyson is introduced; she is seen as having her own weird taste in food, and is hinted as having knowledge that aliens are real. In Big Fat Alien Wedding, Max's brother, Gordon Tennyson is introduced; in the events of the episode Gordon is also a Plumber, still on active duty, as is his wife, Betty Jean Tennyson, and their son, Joel Tennyson.
Max spent his childhood summers on his Uncle Jedediah's farm, where he learned about the merits of hard work.
Max, under the effects of Zombozo's happiness-draining, mentions having been afraid of heights as a kid and to beat his fear he climbed up to the top of the water tower and "scared the fear" right out of him.
Max has a childhood friend called Donovan GrandSmith, who says that Max always worried and was never a risk-taker like him. 30 years earlier, Donovan and Max had both been broke when Donovan offered Max a business opportunity, which he turned down. Max later became a Plumber (most people thought Max was just a regular plumber), establishing that Max's career as a Plumber lasted for about 28 years before he retired (Max mentioned that after 28 years on the job, he'd never figured out who was behind the Bermuda Triangle).
In Moonstruck, Max reveals his past where he first met Verdona to Ben, Gwen, and Kevin (who sleeps after hearing the story). When he was about Kevin's age (16 or 17), he was a pilot in the air force. During a mission, he saw and followed a space ship. He blasted it, but the space ship got away and Max's plane crashed. He talked to the commander about the space ship, which made him an astronaut and gave him a mission to be the first man on the moon. While at a saloon, he met Verdona in her human form and fell in love with her. Suddenly, a giant human robot came and attacked Verdona. Max saved her and left to a far away desert where the robot couldn't find them. Verdona explained to Max that she is not from Earth, she is from another planet. The robot that chased them was a sentient robot called a Synthroid and it left a bracelet on Verdona's hand, which made her unable to do most her powers, save for her telepathy. She revealed to Max that she was the one in the spaceship he saw before she read Max's mind. She told him that their minds are now linked. She also revealed that the Synthroid wants her to be a battery-like energy source for their planet (since she is an energy being). The Synthroid came back and kidnapped Verdona, but Max used his mind to locate Verdona (since Verdona said their minds are now linked). He (with a help from Magister Labrid) saved Verdona and destroyed the Synthroid.
Verdona invited Max to her planet, but Max denied the offer, saying that he has other things to do on Earth. They kissed and Verdona left. The next Monday, he went into astronaut training. Eventually, Max joined the Plumbers after Magister Labrid recruited him. He told Ben that was the story of how he and Verdona met later and said good night to Verdona before he went to sleep.
Max would have been the first man on the moon, but he left the program before the Apollo Moon mission. In his own words, Max said he just 'took his step for mankind in other ways'. It is later revealed that he did in fact go into space, just not with NASA.
Max went to the moon three times and stayed at a secret lunar Plumber base.
Max went up against Vilgax several times in the late 60's and early 70's.
Max retired from the Plumbers in his late fifties.
Ben 10
Grandpa Max is a Plumber, who takes his grandchildren Ben and Gwen on a cross-country trip, during which Ben discovers an alien watch, the Omnitrix. His grandson uses the watch to become the superhero "Ben 10". Max helps his grandson fight bad guys and aliens, and he also teaches Ben to use the watch responsibly.
During their adventures, Gwen and Ben question Max's uncanny knowledge, and the fact he doesn't seem to be bothered by all the weirdness they encounter. It is eventually revealed that Max and the alien warlord Vilgax are old enemies.
Later, Max reveals he is part of an intergalactic police force known as the Plumbers, and that he fought and defeated Vilgax years before. During the episode he meets his old partner Phil Billings. He discovers Phil stole the Null Void Projector, using it to make easy money, by freeing the aliens who the Plumbers had already captured, then fighting and catching them for profit.
In the episode Perfect Day, Max was given superpowers by Ultra Ben in Ben's dream. As Ultra Grandpa he had enhanced strength and was able to fly.
Alien Force
In Ben 10 Returns: Part 1 and Part 2, he leaves a transmission for Ben, stating that he is investigating renewed alien activity on Earth and claims that he has the Omnitrix.
In Max Out, Max destroys a Xenocite hatchery by detonating a Null Void Projector, which after removing its focusing lens, makes a "pretty good imitation of a hand grenade" and produces an explosion that covers over half a mile wide. Max appeared to have been killed in the blast, but was instead sent to the Null Void (episode: Voided), where he, calling himself "The Wrench", fought Dr. Animo, who was calling himself "D'Void". He has since appeared in War of the Worlds: Part 1 and Part 2 to aid Ben in his battle with the Highbreed, along with the "Plumber Helpers". At the end, he takes on the Plumber kids who fought with Ben as his apprentices. He and the Plumber kids also appear in Vengeance of Vilgax: Part 1 and Part 2.
In If All Else Fails, it is revealed that the Highbreed had infected him with a dormant seed, which was part of a failsafe plan of the Highbreed. It is mistakenly activated by a Highbreed officer, who was unaware that the Highbreed has called-off the war. Max is freed from the seeds' control by Ben, Gwen, and Kevin. Also during the episode, he mentions he knew Kevin's father, Devin Levin.
In Above and Beyond, it is revealed by Pierce that Max is now the Earth's Magister (an equivalent to 'Colonel', likely assigned as Earth's Magister after the Highbreed conflict, during which the former Magister Labrid was killed). In the episode, Max set up a scenario in which Ben was to go on a rampage on board an orbiting Plumbers' space station. He then calls the Plumbers' Helpers to come and save him. They manage to defeat Ben, but the battle had caused the space station to fall out of orbit towards the city of London. The Plumbers' Helpers decide to activate the station's self-destruct, which would mean sacrificing their lives in the process. However, the space station doesn't explode. Instead, Max appears along with Ben, who reveals to the Plumbers' Helpers that the space station is a Plumber training facility and that Ben's "rampage" was set up to test them. Max also states that by putting "the safety of others ahead of their own lives", the Helpers will be admitted to Plumbers' Academy.
In the season finale episodes, The Final Battle: Part 1 and Part 2, Max takes part in the fight against Vilgax. When Kevin returns to his human form, Max states that the Omnitrix kept him in his mutated form. Max aids Gwen in trying to stop the ship from crashing into Bellwood. After Ben escapes from Vilgax, he, Gwen, and Kevin share a group hug with Max.
Ultimate Alien
Max has grown to his full potential and is now wiser than in any other series. Since Alien Force, he's been trying to be protective around Ben, Gwen, and Kevin. He makes his first reappearance in the episode Hit 'Em Where They Live, it is revealed that Max has been protecting Ben's parents from being attacked by Ben's old enemies (due to Ben's secret being revealed to the universe). However he is injured while protecting Sandra from SevenSeven and is forced to inform Ben and his team of the problem.
Max appearehd again in Ultimate Aggregor and Map of Infinity, where he helps Ben, Gwen, and Kevin stop Aggregor. However, in the beginning of Map of Infinity, Ultimate Aggregor's electrical shock damaged his entire nervous system, and must be replaced. Azmuth brings him, along with Ben and his team to Galvan Mark II, where Max is placed in a tube that would repair his nervous system after a few weeks.
Max returns in Absolute Power: Part 1 and Part 2 with his Magister's suit, his nervous system having been fully restored and helps Ben and Gwen in the battle to stop Ultimate Kevin.
Max appeared once more in Prisoner Number 775 Is Missing when Area 51 was attacked and was furious when he learn of its alien prisoners being held there illegally and as a result had caused friction between Rozum and Max.
Omniverse
In Omniverse, Max is currently the commander of the Bellwood Plumber base and Earth. Max first appeared in the episode The More Things Change: Part 1 where he tried to inform Ben on something until the alarm goes off. Max isn't seen again in this episode but it is revealed he sent a new Plumber named Rook Blonko to be Ben's new partner.
In The More Things Change: Part 2, Max, along with Magister Patelliday and some Plumbers, arrived to take away Psyphon and his group who caused trouble in Undertown. Max also explained to Ben that the reason he paired Ben up with Rook because he felt that Ben was ready to be a mentor. Ben, at first, wasn't fully up to it, until Rook offered him chili fries.
In A Jolt from the Past, both 61 and 66 year old Max appear in this episode. During a flashback, 11 year old Ben had just defeated the Megawatts using Feedback. Max arrives with rubber blankets, saying how he is glad that Ben still needs them. 66 year old Max appears briefly near the beginning of the episode, where he is upset that Ben was trying to make excuses for being late. Max informs Ben that he isn't working alone anymore.
In Trouble Helix, 61 year old Max mainly appears on a file play-back that was being viewed by Khyber. He goes along with Ben and Gwen to Galvan Prime to tell Ben about the malfunction. Azmuth tells Max to come back in two years to which angers him. Azmuth then decides to fix the Omnitrix after Ben (as XLR8) starts messing with the controls. Max then tells the kids to wait outside while he talks with Azmuth. Max is seen later who tried to help in taking down Malware and rescue Albedo. The plan nearly falls through as Albedo had tampered with the helix trying to destroy Malware rather than save him which turns him into a Negative Mechamorph. Max is told by Ben to rescue Albedo while he'll try to take out Malware as Cannonbolt.
In Of Predators and Prey: Part 1, Max is seen early in the episode trying to catch a scorpion-like alien. Rook aids Max in capturing the alien and Max reveals that he was using the alien in a dish the he and Rook love to eat. Ben informs Max that something is after him and Max asks what Ben should do.
Both the past and present Max Tennyson appears in Of Predators and Prey: Part 2. During the flashback, 61 year old Max drives the Rust Bucket into the large creature known as Terroranchula but it just pushes him aside. Ben manages to fight the creature as Feedback but both the Omnitrix and the Nemetrix time out and the creature turned out to be none other than Phil, a former Plumber. Max watched as Phil was suddenly transported away. 66 year old Max appears briefly at the end of the episode where he rescued Ben and Rook after they escaped from the explosion of Khyber's Ship.
In Outbreak, Max watches as Rook trains with Ben who was using Wildvine. Rook gets beaten by Ben who transformed into Humungousaur and Max told Ben that he needs to learn how to defeats his opponents without using the Omnitrix all the time.
In Gone Fishin', Max appears along with Ben, Rook, and Magister Patelliday who were all going fishing. Everything was going well until large, mechanical robots called Mechaneers capture Patelliday and surround the group. Ben manages to defeat the robots as Juryrigg and the three head to Pirate HQ. Max also replies saying how Patelliday can handle himself while he watches Ben defeat Captain Kork. Rook then presses a button releasing all of the boats that were tapped by Kork.
Max appears briefly in Blukic and Driba Go to Mr. Smoothy's where he tried to contact help in order to help stop Trumbipulor.
In Malefactor, 61 year old Max appears as he told Ben and Gwen about the captured Psycholeopterran at Mt. Rushmore. The alarm suddenly went off and Max, Ben, and Gwen went off to find the source of the problem. It turns out to be Malware's doing and Ben proceeds to fight him but the Omnitrix times out. Max then blasts Malware with the Tachyon Cannon but Malware ends up absorbing the weapon. Max watches as Ben continues to fight Malware as Feedback but then Malware leaves saying "he already has what he came for."
Max appears at the end of Arrested Development where he helps take Billy Billions into custody. When Billions was complaining about Ben taking his credit for saving the world, Max responded by telling Billions to act his age and throws Billions in the Plumber's truck.
In Ben Again, both versions of Max appear where they are confused with the sudden mind change between 11 year old Ben and 16 year old Ben mainly between their voices. 61 year old Max and 66 year old Max soon learned from Professor Paradox that it was Eon's doing and they watch as the Bens used Clockwork to make everything right again.
In Store 23, Max is first seen chasing Liam with Ben. Liam escapes Max but Ben manages to keep up with him as Feedback. Max urges Ben not to use Feedback as there is other aliens in the area but Ben doesn't listen and defeats Liam. Max scolds at Ben for not listening to him and Ben storms off. Max is then seen again at the end of the episode still angry at Ben for running off earlier. Ben then suddenly hugs Max and Max is confused but happy at Ben's attitude.
In Showdown: Part 1, 61 year old Max appears in a flashback where he, along with Gwen and Azmuth, was sitting down talking about Ben's over-usage of Feedback. Ben, greatly upset, then leaves the Rust Bucket without saying much.
In Showdown: Part 2, present Max is first seen talking with an angry Pakmar who demands an apology from Ben for ruining all of his businesses. Max tries to get Ben but notices that Ben isn't even on Earth anymore. Max is then seen much later rescuing Ben, Rook, and Azmuth from the attack of Malware. Max explains that he knew something was wrong when he couldn't find Ben on Earth and used Gwen and her mana tracking powers to locate Ben on Galvan Prime. Max then goes along with Blukic and Driba to try and fix the firewall to prevent Malware from reaching the core and fully taking over Galvan Prime. Max had to give up his belt buckle and his shoe laces in order for Blukic and Driba to fix the firewall which the successfully do. Max is then seen again with his pants still down flying back to Earth along with Ben and the group.