The sloth was a small Earth mammal native to the Amazon.
Prior to 2151, Hoshi Sato and two other teachers from Amazon University took a hydro-skimmer to visit a tributary of the Amazon River. Sato saw sloths, pink dolphins, and many kinds of snakes there, which frightened her a lot. (ENT: "Fight or Flight")
Early production reports described the Xindi-Arboreals as Xindi-Sloths.
In the final draft script of ENT
: "Desert Crossing
", a sloth-like animal on a leash was described as being led by a man, on the Torothan homeworld
. However, no such animal appears in that episode.