Mikaeus, the Unhallowed + River Kelpie + Carrion Feeder

Mikaeus, the Unhallowed

River Kelpie

Carrion Feeder

How it works

1. Activate Carrion Feeder by sacrificing River Kelpie.
2. When River Kelpie dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. When River Kelpie enters, its first ability triggers, causing you to draw a card.
4. Resolve the Carrion Feeder ability.
5. Activate Carrion Feeder by sacrificing River Kelpie.
6. When River Kelpie dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
7. When River Kelpie enters, its first ability triggers, causing you to draw a card.
8. Resolve the Carrion Feeder ability.
9. Repeat.