Ordinary Pony

When this creature enters, you may exile target non-Horse creature you control that wasn't put onto the battlefield with this ability this turn, then return it to the battlefield under its owner's control.

Unsanctioned

When this creature enters the battlefield,
you may exile target non-Horse creature you control that wasn't put onto the battlefield with this ability this turn, then return it to the battlefield under its owner's control.

Unstable

When this creature enters the battlefield, you may exile target non-Horse creature you control, then return it to the battlefield under its owner's control.

Host creatures each have an ability that triggers when it enters the battlefield. It functions like any other creature.

This card has received minor errata so you can’t flicker creatures more than once each turn. Oops.