He commands a sizable army consisting of both robot subjects and the ninja-like Blood Monks of Morbidia; he is also one of the larger collectors of rubber and glass ducks. He loves ducks. And he is the "father" of The Betty Clones. Despite his hatred of Betty, he has occasionally teamed up with her: either to foil the plans of his own father, Max Sr., foil his own grandfather, Max Sr. Sr.'s plans when he was picked on by his grandfather (with his father to back him up due to both of them hating him), or, in "Takes One to Know One", to recover one of his stolen ducks from the villainness Pandora.
Among Maximus' goals is to locate and destroy Galactic Guardian headquarters, as well as to locate and destroy Betty's home planet. He manages to do the first former in "No Space Like Home", and has come close to doing the latter on numerous occasions, before ultimately being repelled by Betty each time. Also in the episode No Space Like Home, he wanted to destroy Galactic Guardian headquarters until Noah and Minimus, both whom were playing catch, unintentionally destroyed the Galactic Guardian's HQ and this causes Maximus to be upset and he yells that he was robbed of his revenge. In Mission: Earth, his two goals have become the same, following the relocation of Galactic Guardian headquarters to Moose Jaw.
In the Mission: Earth episode, Noah's Bark, it turns out that his species is a Felinian and that he was banished from his home-world. Wanting revenge on his own kind for what he perceived as an insult, though some believe that it contradicts his earlier statement that Maximus' home world is Splatzy (though it could mean that Splatzy was his current home world for after he was banished from Felinia). He came up with a plan to take the planet of either his kind or their neighbors of the planet Canus Dogillia. Maximus staged attacks on the Dogillians, making it look like the Felinians were attacking them, and provoking the two planets into war. He planned to take the planet of either the dogs or the cats, depending on who lost the war. Later, however, his plans were revealed and he was punished by being turned into a dog by the leader of the Dogillians, Mr. Snugglekins to teach him a lesson after Noah, who had also been turned into a dog learned the dog credo, a lesson Maximus, unfortunately, must learn himself.
His most complex plan culminates in "The Future Is Now!", when he travels into the future (with Sparky, X-5, Beatrixo, and Admiral DeGill as hostages) using X-5's recently-built time machine in a bid to take over the Earth; however, Betty and Noah manage to elude capture. By 2013, he had manage to enslave all of Moose Jaw, including the Galactic Guardians, centering his stronghold in Beatrixo's farm. Betty and Noah manage to repair an old nonfunctional prototype time machine and pursue Maximus into the future, but they, along with the remnants of the Galactic Guardians (Betty, Noah, Chaz, Regeena, and Penelope of 2013 though the latter was just hanging around), are captured. Betty manages to trick Maximus into "repairing" his time machine, but the Galactic Guardians of 2013 manage to distract Maximus long enough (using Penelope's desire for fashion to help out and fight against them) for Betty and Noah to take control of the time machine themselves. Returning to the past, Betty and Noah convince the Galactic Guardians to instead present their nonfunctional prototype time machine, which Maximus subsequently captures, though when he and Minimus try to use it, they both become gelatin-like.
- Though it's debatable and despite him being based on Ming the Merciless, the robe in which Maximus always wears is similar to that of Dracula's from the movie Bram Stoker's Dracula in which both had worn a long red robe.
- Colin Fox, Maximus's voice actor, is no stranger to extraterrestrial characters; he voiced the Watcher on the short lived Silver Surfer animated series. He also played the Mask Maker on the Goosebumps series in the two part episodes, the Haunted Mask and the Haunted Mask II.