I'm agreeing with the Antlion suggestion; if Graboid didn't exist everyone would be using Shrieker rushes with Antlions instead of the obvious. Completely overlooked.
Personally I think it is in general quite weak. Yes it stops 50% of damage, but only after you have already suffered the amount. Dusk is better at 50% and may prevent it in the first case.
actually, i think damselfly is the most underrated card, no AI uses it and maybe only 1% of players use it, and i think it could make some pretty cool air rushes.
There is a deck using 6 damselflies though....but the unupped....neh.