Tyranid Harridan

Flying, ward {4}
Shrieking Gargoyles — Whenever this creature or another Tyranid you control deals combat damage to a player, create a 1/1 blue Tyranid Gargoyle creature token with flying.

The Swarmlord

Rapid Regeneration — The Swarmlord enters with two +1/+1 counters on it for each time you've cast your commander from the command zone this game.
Xenos Cunning — Whenever a creature you control with a counter on it dies, draw a card.

Tyranid Invasion

Create a number of 3/3 green Tyranid Warrior creature tokens with trample equal to the number of opponents you have.

Tyranid Prime

Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
Synapse Creature — Other creatures you control have evolve.