The VOIDRUNNER'S CODEX is coming! Explore new worlds, fight oppressive empires, fend off fearsome aliens, and wield deadly psionics with this comprehensive boxed set expansion for 5E and A5E!
Thanks. At least I know why I missed that one -- it's an "Opabinia, Giant" in Dragon #176, but just an "Opabinia" in Dragon #204 and Dragon #348, so on a casual inspection it looked like two different creatures . Now fixed!