Magmar

At the beginning of your upkeep add {r}{r}.
Whenever a red source or ability which cost {r} effects Magmar, prevent the damage or effect
on Magmar and it gets +1/+1 until end of turn.
{r}, {t}: Magmar deals damage equal to its power
to target attacking or blocking creature. If that
target is green, snow or an artifact, this ability
deals that much damage plus 2 instead.