Black Fairy

The Black Fairy is a character that appears in Once Upon a Time, played by Jaime Murray.

She is Rumplestiltskin's mother, who she abandoned as a child.

She kidnaps children for unspecified, yet sinister, reasons. When she attempts to kidnap an abanboned child in front of the adult Rumplestiltskin, he paralyzes her with Squid Ink, long enough for Belle to fend off the Black Fairy and thus save the abanboned child.

The Black Fairy recognizes Rumplestiltskin as the Dark One and taunts him over it, claming that the two aren't so different. However, this doesn't affect Rumplestiltskin, since he's more of an anti-hero as opposed to the more villanous Black Fairy.