Lucas was a) fascinated by this weirdo horned creature that looked a lil' bit like a yeti but was cooler because it was so dangerous and b) grossed out by this weirdo horned creature. His first instinctual answer had been the jelly legs curse (something he'd come across his vast, read: sparse, preliminary readings) but that had been said, twenty times over so he just took notes.

What did LEVICORPUS do? Now that was a good question.