Mikaeus, the Unhallowed + Lithatog + Pith Driller

Mikaeus, the Unhallowed

Lithatog

Pith Driller

How it works

1. Activate Lithatog's first ability by sacrifiicing Pith Driller.
2. When Pith Driller dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
3. When Pith Driller enters the battlefield, it triggers, putting a -1/-1 counter on it.
4. Resolve the Lithatog ability, giving it +1/+1 until end of turn.
5. Repeat.