User blog comment:Supahbadmarine/New Tyranids/@comment-1583177-20100901105009

If the planets rocky replace some tyranids legs with snake tails, not just ravenors ad trygons but carnefex's, hive tyrants, even gaunts!

Also if its a water world add gills and make a webbed on the end of the gaunts tail.

Stuff like that you know!