Kjeldoran Guard 

Creature — Human Soldier
: Target creature gets +1/+1 until end of turn. When that creature leaves the battlefield this turn, sacrifice this creature. Activate only during combat and only if defending player controls no snow lands.
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyLEGALvintageLEGALcommanderLEGAL