Faerie Miscreant’s triggered ability checks to see if you control another creature named Faerie Miscreant at the time the new Faerie Miscreant enters the battlefield. If you don’t, the ability won’t trigger at all. The ability will check again as it tries to resolve. If, at that time, you don’t control another creature named Faerie Miscreant, the ability will have no effect.

If multiple Faerie Miscreants enter the battlefield at the same time, all of their triggered abilities will trigger.