Thoughtweft Lieutenant is a uncommon Creature — Kithkin Soldier card from Lorwyn Eclipsed (ECL), collector number 343. Current market price: $0.16 (foil $0.31), TCGplayer market prices via Scryfall.
Whenever this creature or another Kithkin you control enters, target creature you control gets +1/+1 and gains trample until end of turn.