So, I'm having a few problems with some creature designs I'm doing for me and Keb's space animal project, and I thought I'd ask for your help. You don't need to be familiar with what I'm doing or even to know that much about creature design, I just need a few suggestions or discussions to get me to work round the issues.

Basically we're working on an ecosystem in space, the problem is I only seem to be able to take living animals and alter their physiology a bit whenever I try to think of a new animal, which is interesting to me but not so great in terms of design when all the interesting differences are internal. The one I'm stuck on at the moment is a stationary hunter that grabs anything that comes close, a bit like a sea anemone, so I'd really appreciate any suggestions as to things it should be able to do, anatomical features that may be useful, or just cool animals I might be able to look at for inspiration.

If you can't think of anything to help with that particular case, then any more general help along the same sorts of lines would also be greatly appreciated.