- "Bad Kitty!"
- ―Eunice to Diego[src]
As the mother of a sloth named Sid, Eunice was responsible, along with the remainder of her family, for abandoning her son while the rest of the family migrated off.
Eunice, along with her family, had always been compelled to remain with Sid, who remained a nuisance to the others. Throughout the years, Eunice and her family continued to try to leave Sid behind. One year, the family succeeded in stopping Sid from following them by gagging him with a field mouse, tying up his hands and feet, barricading their cave entrance and moving through water so that Sid would lose their scent. Sid found them regardless, and joined them for another migration until the year that his family woke up early and left Sid behind.
Eunice and her family, consisting of her husband Milton, their son Marshall, the elderly family matriarch Granny, and the family's uncle, Fungus, returned to find Sid, traveling down the snowy mountains in a hollowed-out log which they had tied Granny to. During the ride, the log hit a Saber-Tooth Tiger named Diego, who Eunice hit in the face before the family of sloths were compelled to hold on tight as the log hit a rock, flinging Diego towards the back of the log, as Milton and the others ducked.
Moments after, the log stopped and they were all flung out of it, nearly colliding with a number of other animals. Moments later, Eunice's son Sid arrived on the scene, and was overjoyed at seeing his family again and embraced his parents and brother. At first, Eunice and the rest of the family acted as though they were happy to see Sid again. But once they had Sid lead Granny away and both were out of earshot, Eunice and the rest of Sid's family cheered aloud at getting rid of Granny and rushed back to the log, pushing it towards another downhill slope. While Fungus and Milton were helping to push the log, Eunice explained to Manny, who called out that they couldn't simply abandon Sid again, that things were falling apart back home and that Granny was dead weight. The four sloths then ushed off inland on their log, never to be seen again by Sid.
Like most of the rest of her family, Eunice was shown to be extremely shallow and uncaring towards her own kin; always attempting very hard to get rid of her own son Sid, abandoning Granny as dead weight, and returning to Sid only to dump Granny on him and then abandon him again; all without any qualms whatsoever. She was also shown to be a very poor motherly figure in this respect and that she was shown to sometimes carelessly bump Marshall aside when he was unintentionally in her way.
Behind the Scenes
Eunice was voiced by comedienne Joy Behar.