Garenbrig Paladin 

Creature — Giant Knight
Adamant — If at least three green mana was spent to cast this spell, this creature enters with a +1/+1 counter on it. This creature can't be blocked by creatures with power 2 or less.
Legality
standardNOT LEGALpioneerLEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL