Primal Rage

Creatures you controll have trample.

"To think that Tyranids are mindless beasts is a grave
mistake. When you fight Tyranids you face not only
those before you on the battlefield, but the untold thousands which seek to surround you, which attack
your supporting units and destroy your supply lines in perfect synchronicity. These aliens have shown
evidence of both tactics and strategy that speaks of a
far worse threat than that posed by a mere beast."
- Marneus Augustus Calgar