Krakentooth

When Krakentooth enters the battlefield it
Fights target creature you don't control. If {b} mana was spent to cast Krakentooth, it gains
+2/+0 until end of turn. If {u} mana was spent to
cast Krakentooth, Investigate.
"This one was made for battle, and this one knows
how to find it." Krakentooth missunderstanding a
common human saying.