The Alvanian cave sloth was an animal known for its constant pacing and for deep sleeps.
Quark told Rom that pacing around the bar like an Alvanian cave sloth wasn't going to help Nog get into Starfleet Academy. (DS9: "Facets")
While traveling aboard runabout, during the quest to find the Sword of Kahless, Kor awoke and emerged from the rear section, and stated that he slept like an Alvanian cave sloth. (DS9: "The Sword of Kahless")