Billy got him when his dad decided to go fishing but Billy thought that fishing was cruel to animals, so he went to the pet store to find the perfect fish for him, the one he picked who was very tiny and sickly and decided to call him Lil' Porkchop. Grim feels sorry for Porkchop because he's afraid that he won't make it through the night, so he gave him some growth vitamins. He did this because he had a pet fish as a kid, which was a skeleton.
The next day Porkchop is a giant and has gained the ability to speak with a voice highly reminiscent of Arnold Schwarzenegger. Billy thought it was his love that made him grow, he warns Billy about global warming and how it will affect the Earth but he pays no attention and brings him outside in what was said to be the hottest day of the year, the sun soon starts to cook Porkchop and make his scales peel off, when Billy sees this he takes him to the spa to feel better but it only makes his condition worse, later Billy decides that he's hungry so he takes him to a Chinese resturant which terrifies Porkchop because the employees tried to cook him as he runs outside the resturant where he collapses, dies, and crumbles to pieces.
Billy is heartbroken so he gathers his remains and holds a funeral for him as he flushes each individual piece of him down the toilet. Grim and Mandy come by with the cure for his growth, but came too late. Later Billy's dad arrives back from his fishing trip with a fish that looks exactly like Lil' Porkchop, Grim explains that sewer water was the antidote and it reverted him back to his original form. Lil' Porkchop was brought up twice in later episodes when Mandy and Grim mention what a terrible pet owner he is. He appeared in Keeper of the Reaper in his giant form because of how Billy mistreated him.
- Lil Porkchop's accent and size (after Grim magically sized him up) is a clear take on famed Austrian-American actor Arnold Schwarzenegger.
- His comments about how the air is running out can be a reference to the Schwarzenegger film Total Recall, where the plot involves the oxygen supply in a colony on Mars.