The Va-Tso

Vigilance
When The Va-Tso blocks or becomes blocked by a creature, exile that creature. At the beginning of your upkeep, put all creatures exiled this way onto the battlefield under your control, except they lose all abilities, are green, and are a Plant Drone in addition to their other creature types.
When The Va-Tso leaves the battlefield, return all creatures exiled with to the battlefield under their owner's control