For some reason the baby spider can still hit you when he is in the death animation.

You mean for a short moment while the animation plays or did he persistently appear as dead and kept attacking you? The first one I don't really see as a big issue.

I have had a similar issue with baby spiders but they continue to hit me after the death animation as if they are invisible. For me, they just keep attacking me until I die but I can't see them. I had to turn them off in the config because of this.