Multiattack.The King of Feathers makes two attacks: one with its bite and one with its tail. It can't make both attacks against the same target.
Bite.mw 10 to hit, reach 10 ft., one target. ({@damage 4d12 + 7) piercing damage. If the target is a Medium or smaller creature, it is grappled (escape 17). Until this grapple ends, the target is restrained, and the tyrannosaurus can't bite another target.
Tail.mw 10 to hit, reach 10 ft., one target. ({@damage 3d8 + 7) bludgeoning damage.
Summon Swarm 5.The King of Feathers exhales a swarm of wasps||swarm of insects (wasps) that forms in a space within 20 feet of it. The swarm acts as an ally of the King of Feathers and takes its turn immediately after it. The swarm disperses after 1 minute. It can't use the Summon Swarm action while it is grappling a creature with its jaws.