Acid venom? Yeesh. I thought it was just snake venom, which is bad enough (and that was only because he caused Baldr to die, with the old mistletoe trick. And also because everyone liked Baldr so much). Heck, if Baldr wasn't so popular, they wouldn't do that to Loki - or his son Narfi. (Poor Narfi. What did he do to deserve that?)
I'll bet you that's one scene they'll never film. =P Killing Narfi and using his entrails to bind Loki ... yuck!
Speaking of which, why does the Marvel Loki have that silly-looking helmet? I know the "horned helmet" motif is one that's frequently associated with the Norse (thanks, Wagner), but just looks silly.