Fish

Level Up (You may pay {x} at any time to level up
this creature, where {x} is its level plus 1. Also it
starts on level 1.)
Level 1 - Level-up: Give all creatures you control
+1/+1.
Level 2 - Level-up: Give all creatures you control
+2/+2.
Level 3 - Level-up: Give all creatures you control
+3/+3.