Jaghatai Khan, the Warhawk

Haste, trample
Each creature card in your hand has dash. The dash cost is equal to its mana cost. (You may cast the spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)
Whenever another creature enters the battlefield under your control, that creature gets +2/+2 and gains trample until end of turn.