Eventide

Grazing Kelpie

{GW}, Sacrifice Grazing Kelpie: Put target card in a graveyard on the bottom of its owner's library.
Persist (When this creature is put into a graveyard from play, if it had no -1/-1 counters on it, return it to play under its owner's control with a -1/-1 counter on it.)

{G/U}, Sacrifice Grazing Kelpie: Put target card from a graveyard on the bottom of its owner's library.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)