What is a hog catipillar?

There is no such thing as a "hog caterpillar."

It's likely you're thinking of a caterpillar with a unique feature or name that you're misremembering. Could you provide more details about what you remember about this caterpillar? For example:

* What color was it?

* What size was it?

* Where did you see it?

* What did it look like?

With more information, I might be able to help you identify the caterpillar you're thinking of.