Bonzello's Frontliner

Exalted (Whenever a creature you control attacks alone, it gets +1/+1 until end of turn.)
{t}, {3}{r}{r}, Sacrifice Bonzello's Frontliner:
Target attacking creature you control gets
+3/+0 gains trample and doublestrike until
end of turn. Activate this ability only if
there is one attacking creature.