As long as Tormund Giantsbane, Freefolk Lieutenant entered the battlefield this turn it cannot attack.

Boast — {X}: Create X 1/1 Human Berserker creature tokens that are tapped and attacking, then creatures you control get +X/+0 until end of turn, where X is the amount of {S} spent to activate this ability. (Activate this ability only if this creature attacked this turn and only once each turn.)