A Grubhog is a larva of an unknown beetle. It is the subject of Grubhog Day. During the holiday, the selected grubhog is cut open, down to the liver. The number of spots determines the weather of the coming seasons by Wartwood local tradition.
It is mostly a creamy-yellow color with a large brown head. Its eyes are a light teal, with faint brown, slit pupils. It has two little round antennae on the top of it's head. Mysteriously, being the larva of an insect, the Grubhog has eight legs. The extra legs are most likely prolegs. It has a brown spot on each side of each segment along its body. It also has a short brown snout similar to that of a pig's.
It appears to be the Amphibia's equivalent of a pig, since it has a pig-like face, sounds like a pig, and has "hog" in its name.
- In the episode "Grubhog Day", it is revealed that the Grubhog was in fact rescued by the vulture which picked it up and that they were now going to 'war'.