Dear all,
Thanks for the copyright education. I added the title of the work and a link. (It's creative commons.)
I did mean the creature to be single-use and random, not targeted. Also, note that the Crow | Raven has one hit point, so there are plenty of ways to prevent it from killing something. I also thought, and should probably add, that an immaterial creature wouldn't be killed by it.
@OdinVanguard: I like the idea of "marking" a creature thematically, but I thought it was more balanced to allow your opponent a turn to get out of it.