There is nothing wrong with seeing further hybridised versions, so long as they're done right. That crocodilian one... Aside from the tail being vaguely more reptilian at the base, it's f**ked up. They should have at least done something to make the jaws larger and more viciously capable. Alligators don't tend to be fat, either. That thing looks like it came out of a damn brontosaurus.
I have yet to see an Alien hosted from something other than human, in the comics, which actually looks good, but I know it could be done.