Crook Bark, Bone Clan Slacker

Vigilance
{u}{u}{g}{g}, {t}: Gnomes you control phase out, then if three or more gnomes phased out this
way each opponent creates a colorless trickster artifact token. (It’s an artifact with "The next
time you would tap one or more lands for
mana, instead tap all lands you control and
empty your mana pool then sacrifice this artifact.)"