Ant-One is a small piece of charred toast. He possesses a more jagged and maw-like mouth than Anton, his eyes are saggy and his eyebrows slightly larger. Ant-One has skinny black limbs, and wears burned gray-white gloves and scorched little white, purple and gray shoes.
Ant-One was psychotic and obsessed with destroying the original Anton to try and make Gumball and Darwin accept him as their child and be his parents. Despite his hatred of the other Antons, Ant-One was still willing to use the fallible and easily-manipulated clones as his slaves and henchmen. As well as being insane, AntOne was apparently very aggressive and intolerant of failure; shown in how he knocked Richard over the head with a garden tool, and how he gruesomely wiped out his Anton army using the school fire sprinkler system when they proved useless in a fight against Darwin. Ant-One could be melodramatic and arrogant as well; as he declared when Gumball stopped him and Ant-Two from falling off the diving board into the school pool that he'd have to let both of them fall, when Gumball was actually strong enough to easily hold on to both of them.