In Once Bitten, despite that he was bitten, he somehow managed to survive the infection (or thinking he was infected) therefore he never became a zombie. He was able to stand upright as well. He is seen in the mob of survivors that are using the Krusty Krab as a safe zone.
In Gullible Pants, he walked into the Krusty Krab, and SpongeBob went up to him, stating that he knew his secret. Not wanting his secret to be revealed, as his words to SpongeBob were "What! Who told you?!", he follows SpongeBob to the kitchen, and begins to grill the patties.