It's possible you're thinking of a mythical creature or a fictional creation. There are many fantastical creatures in stories and folklore with unusual features, like a pig with thorns.
Here are some possibilities:
* Mythological creature: There might be a creature in a specific mythology or folklore that resembles a pig with thorns.
* Fictional creature: It could be a character from a book, movie, or video game.
* Misinterpretation: Perhaps you've seen an image or description of a creature that was misidentified or misunderstood.
Could you provide more context about where you encountered this idea? Knowing more about its origin might help us understand what you're thinking of.