Amuncommon is voiced by Cindy Robinson.
As the head of the family, Amuncommon is very stern and commanding, and has little patience for foolishness. She is not a fan of modern music, something Seth loves but has to keep secret from her. She agrees to Ramses de Nile's plan to unite the two families, believing it will be the best decision for her son. After the events of the movie, she accepts that Seth wants to be a musician, now knowing what truly makes him happy.
Amuncommon is a tall, dark skinned mummy with angular features. She wears a black business suit with gold trim, and a Egyptian-style headdress.
The De Niles meet Lux Ptolemy and her son Seth. Though "Boo York" Ptolemy insults modern music, while her son on the other hand loves it and has to go behind her back to be able to preform. Next morning, the De Niles, Ptolemys and the other ghouls settle down at a banquet, only for Deuce to dress like going to the beach, embarrassing everyone. The guards then put him in a blazer which catches fire on a candle since it's too loose. The fire is extinguished but everyone is affected. Nefera later convinces Deuce he doesn't belong with Cleo. At the same time Ghoulia tracks down the comet only to find it will land in Boo York. Later that day, the ghouls run into Luna who now works for a pizza parlor.
The crystal comet party commences, with the ghouls, Ptolemys and De Niles attending. Cleo and Seth are to have a promise ceremony as the two of them are destined to summon the comet together. As Ptolemy and Ramses de Nile agree to an arranged marriage between her son and Cleo. Halfway, Seth takes off his mask and reveals he is indeed Pharaoh, then speaking up against Lux. As Ptolemy is shock at this, as Catty and Pharaoh run off together.
Near the end of the movie she accepts that Seth wants to be a musician, now knowing what truly makes him happy. And even approves of his relationship with Catty Noir.
Amuncommon's son is Seth Ptolemy. She seems to have raised her son with equal if not stricter regulations as Ramses de Nile has for his own daughters. While she does initially have problems for her son's real likes and personality, in the end she is accepting of Seth's love for music and having a relationship with Catty Noir.
- September 29, 2015: Amuncommon makes her debut in the TV Special Boo York, Boo York.