Pregiarize
When you come up with a fantastic idea only to be told that it has already been done, you may accuse the person who did it first of pregiarism-- pre-plagiarism.
Alice: Ok, so I had this fantastic idea for a superhero: he's a mutant, and he drains the life force of anyone he touches, so it's a great weapon but it also sucks because--
Bob: Yeah, that's Rogue. From X-Men.
Alice: ARRRRGGH stupid Marvel pregiarized my idea
Bob: Yeah, that's Rogue. From X-Men.
Alice: ARRRRGGH stupid Marvel pregiarized my idea