The Hive Tyrant, Tyranid Prime, and Tervigon may take the Bio-Artefacts.
Giving a Tervigon an artifact might be interesting.
Like the Norn Crown and taking Dominion Pyschic power. Or taking the Miasma Cannon. The Reaper of Obliterax is probably a bit much on the price for a tervigon, however, I5 on a Tervigon could be worthwhile, especially since you also gain the possibility of Instant Death. Not to mention I5 allows the Tervigon to go toe to toe with Dreadnoughts.
Like most of the 'best' Artifacts in the 6th Edition, the 'super' weapon is on the high price tag side.