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.
Max still has his red floral shirt, with a black one below it. He wears brown pants, the Plumbers badge is located on his belt and he wears white shoes. He also has a white moustache nowadays.
An easy-going, kind, and normally jovial man, Max Tennyson often comes across as pleasantly absent-minded at times, but is actually quite perceptive. For instance, he knew early on in Ben's adventures who was most likely pursuing him, as he was aware of Vilgax's history having fought the alien tyrant many times before. Max is also a very brave man, having dedicated his life to preserve peace on Earth between humans and extraterrestrial life. His bravery has resulted in him being injured, having his DNA spliced, nearly killed in several dozen ways, and more. His prioritization of others' safety above his own even when bereft of a weapon shows his selfless nature at its finest. The consummate strategist, Max is very intelligent, being able to select the correct weapon to battle Z'Skayr based on minimal information given to him by Ben, choosing a light-based weapon to bring down the rogue Ectonurite.
Though well-meaning, Max is not without a stern side, having struggled to guide Ben during the first few months of his grandson's possession of the Omnitrix. When pushed, Max can be strict, harsh, but not unreasonably so, not being afraid to call people out on their selfishness and mistakes when necessary.
Max has a weird appetite, which comes from his travels both on the Earth and beyond.
Powers and Abilities
Although Max doesn't have any super powers, he is very skilled in combat and can take on anyone who does have them as he is quite athletic for someone of his age. As a retired Plumber, he has access to a variety of various Plumber tools and weaponry, which he uses skillfully. Aside from that, his experience from his Plumber days made him knowledgeable on various species of aliens. He is also able to strategize well and is skilled in inventing new machines. He is telepathically connected to his lover, Verdona.
Before joining the Plumbers, Max was a United States Air Force pilot, with dreams of joining NASA and going to the moon. He was an expert at flying an F-104 Starfighter and was able to shoot down an alien spacecraft.
Max has a Plumber uniform and badge.
Despite being highly trained, Max is far from the prime athletic specimen he was during his days as a Plumber. He is a senior citizen, and has not managed to keep in shape, though he does still possess an incredible tactical mind to compensate for his less than stellar physical conditioning.