Thunderfoot Baloth

Trample
Lieutenant — As long as you control your commander, Thunderfoot Baloth gets +2/+2 and other creatures you control get +2/+2 and have trample.

Saskia the Unyielding

Vigilance, haste
As Saskia the Unyielding enters the battlefield, choose a player.
Whenever a creature you control deals combat damage to a player, it deals that much damage to the chosen player.

Hydra Omnivore

Whenever Hydra Omnivore deals combat damage to an opponent, it deals that much damage to each other opponent.