Pack Mastiff

This land enters tapped. When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.) T: Add U or R.

5UU: This creature can't be blocked this turn.

Flying (This creature can't be blocked except by creatures with flying or reach.) Vigilance (Attacking doesn't cause this creature to tap.) Other creatures you control have vigilance.

(T: Add R.)

(T: Add B.)

Return target creature card from your graveyard to your hand.

During your turn, this creature has lifelink.(Damage dealt by this creature also causes you to gain that much life.)

Put target creature with power 4 or greater on the bottom of its owner's library.