Mangoose
Arcane
Outside of Genestealers and Tyranid Warriors drastically changing looks, the rest of the Tyranids mostly just had a head change, arguably the heads do look Zergy. http://www.dakkadakka.com/dakkaforum/posts/list/269155.pageNew Tyranids which came out a few years after Starcraft looked more like Zerg than like the old Tyranids.It's been the other way around mostly, for historical reasons.They did rip off Starcraft, though.
In any case they both intentionally ripped off from Alien