Zomom's two dominant traits are his lack of intelligence and his boundless appetite. He is not very bright, possessing a very simple way of thinking, and can sometimes end up embarrassing himself. He is also somewhat bumbling and slow, often causing damage when fumbling around without realizing it, failing to understand figure of speeches, and could only distinguish Sonic and Tails due to their color. Regardless, Zomom is aware that he is stupid and embarrassing, though he does not wish to appear any worse than he already is.

Zomom is a gluttonous Zeti with an unlimited appetite and will eat just about anything or even anyone.  Just seeing or mentioning anything food-related can stir up his appetite and he can easily be motivated or distracted by food. However, Zomom is somewhat sensitive about his size. While not showing any dislike of his own about his chubby appearance (bordering on denial of it), he gets hurt emotionally and even threatening when someone calls him "fat" or makes fun of his size. Zomom also appears to have low self-esteem; he wonders if it is possible to make him look any worse, and upon being defeated, says that his mother was right about him being a failure.

Like the other members of the Deadly Six, Zomom is inherently malicious, sadistic and violent. He takes great enjoyment in causing pain, inflicting physical punishment and killing others, and finds fun in hostile violence. An omnicidal monster, he has no qualms about causing massive genocide for his own gain. Zomom also comes off as vengeful, given that once he was freed from Eggman's enslavement, he launched an attack on the scientist, and afterward wanted to squeeze Eggman to death and eat him.

His personality takes a drastic turn in "Sonic X Dimensions", where after obtaining the element of Sorrow, he beings to see the folly of how he's lived his life prior, beginning to regret being a glutton and seek the help of others. He also begins to care about his other Zeti, something which never happens before

He is voiced by Patrick Seitz, example of his acting can be found here: https://youtu.be/BGj3_MXeqLI?t=431