Incubation Chamber

Incubation Chamber does not untap during your
untap step.
At the beginning of your upkeep put an incubation
counter on a target creature token in exile with an incubation counter on it, and if it has 3 or more incubation counters on it, put it on the battlefield. If
target token creature was put onto the battlefield,
untap Incubation chamber,
{t}: Choose target creature card, create a token that's
a copy of target creature and put it into exile with an incubation counter on it.