Mr. Ball Legs is an, approximately fist sized, liver-coloured, organic "ball", which a person throws up with the insane amount of vomit in the transformation process into an undead person. Mr. Ball Legs appears very early in the show in episode 1/S1, called So Then a Bat or a Monkey, when Sheila Hammond suddenly falls ill and throws up the then not closer defined red organ-like tissue. Sheila turns into a Zombie and Joel Hammond packs her meaty ball up in episode2/S1 We Can't Kill People! and takes it to virologist Dr. Hasmedi at City College. His attempt to discover more about the strange "organ" almost brings him a lot closer to psychiatry.
Later in the show, it turns out, that everytime, when somebody is turned into a Zombie, the person will throw up one of those red meaty balls (plus an enormously insane amount of vomit). Sheila's "Mr. Ball Legs" spends his first days in a lot of olive oil and then in the Hammond's freezer, because the Hammonds don't exactly know what to do with it, but still hope, it might help in a cure for Sheila.
It turns out, that Ramona from the Rite Aid store, is a Zombie, too. From her, the audience will learn, that the ball is actually a creature, which also grows spider-like legs and has disturbingly many eyes all over its body (mostly at night).
Joel Hammond never liked Mr Ball Legs, but he grew on him. In the huge cliffhanger of the last episode of S3, the ball climbes into Joel's ear and makes Sheila finally turn Joel with a bite. then cuts to gene tommy and and accomplice who are mad about sheila
- The character Ed Thune is turned into a Zombie, but then goes feral, so Joel has to kill him and his Mr. Ball Legs. Inside, the red balls are also filled with black goo.
- In their attempt to find meat for Sheila, the Hammonds try to kill a man named Loki Hayes, but instead turn him. Lokis Mr. Ball Legs also ends up in the freezer, when Loki finally is killed.
- Mr. Ball Legs is also called "Mala Draga" in the old serbian book.
- The creature appears on the shields of the Knights of Serbia and in the last episode on the uniforms of Sheila's followers.
- The creature will fall ill and eventually die, when their host is not near. That's why the Hammond's eventually call Ramona, who missed her little "friend", too.