Hostile islet

{u/b}, pay 2 life: Until end of turn, Hostile islet becomes a 3/4 blue and black crocodile creature with Dismember (Whenever this creature is blocked, put a -1/-1 counter on the blocking creature and create a 0/1 colorless Appendage creature token.)
Sacrifice an Appendage: add {c}{b}{u} to your mana pool.