Arboreals were susceptible to a certain type of mutagenic virus created by the Loque'eque. (ENT: "Extinction") Arboreals were afraid of water and were considered to be lethargic by the other Xindi species. They were also extremely calm, even when taken hostage. (ENT: "The Shipment")
Culture and technology
Relatively speaking, Xindi-Arboreal starships were not very powerful; a Xindi-Reptilian starship patrol could easily destroy three Arboreal ships. (citation needed • edit) One particular Arboreal vessel was small, incapable of outmatching an Osaarian merchant ship and contained a component that had Xindi writing on it. This Xindi craft also carried fuel, supplies and the Xindi database. (ENT: "Anomaly", "Extinction")
|Aquatic • Arboreal • Avian • Insectoid • Primate • Reptilian|
In the final draft script of third season Star Trek: Enterprise premiere "The Xindi", the Xindi-Arboreals are commonly referred to as "Xindi-Sloths". This was changed by the end of that season, as scripts for installments such as "Countdown" and "Zero Hour" instead refer to them as Xindi-Arboreals.
When designing the Xindi-Arboreals, there was only enough time to draw a tiny pen sketch of the facial design; most of the work that went into conceiving it was done by sculpting clay, which was begun after the makeup artists realized which direction they wanted take the design in. Although Makeup Supervisor Michael Westmore found that the Xindi-Arboreal makeup was one of the easiest to put together in general, the design ended up involving prosthetic masks whose frontal hair was a large challenge and presented him with much work. Each mask included not only facial hair but also some head-hair. Westmore implied that the Arboreals were probably vegetarians by giving them large teeth, which were almost like horse teeth and were twice the size of Human teeth. Contact lenses were not deemed necessary, as at least most of the actors who were cast to play the Arboreals had very dark eyes.
For each of the Arboreal-playing performers, nails – similar to those of a sloth – and hair were crafted into a pair of gloves. "So they can literally put their arms on and go to work," Michael Westmore said of the actors. "This is the first time we've done that with [an alien] [...] this complex."
The Arboreals were made to feature a variety of shades. "They range from light beige to darker brown undertones on the skin," noted Michael Westmore, "and then the hair that grows over them is different – from gray to blond, red to gray, like there's an underbase and an overbase to the hair."
For the Arboreals' head-hair, Hair Designer Michael Moore obtained fur fabric samples from National Fiber Technology. "I started looking at 'em and began to think, 'Hmm, this'd work.' It was more like a hood than a wig; I basically put it on a head form upside down to put it together, and then when I reversed it the hair was all on the outside." During production on Enterprise's third season, the makeup and hair departments blended their two respective types of head-hair. Any potential of a hard line between these was avoided by covering a strip of hair – which looked virtually Human and was at the front edge of the wig – with the hair Michael Westmore had crafted into the back of the mask's top. Moore's main concern with the wig was maintaining the stripe down the middle of the head.
Costume Designer Bob Blackman located the fabric for the Arboreal ambassador robes at KADD Leather, in Santa Monica. This material, along with the word "sloth," triggered the idea of how to design the clothing for the species. Blackman described the fabric as having an "amazing reversed rabbit-skin, ancient hide look" and went on to say, "It had a weird antiqued finish, one you don't usually find – something that's been made to look ancient. Each hide has six squares sewn together, so it was a patchwork thing." (Star Trek: Communicator issue 149, p. 53)
Executive Producer Rick Berman once commented that, of all the Xindi species, he thought "the Xindi-Sloth" looks especially good. (Star Trek: Communicator issue 147, p. 16) With similar gusto, Archer actor Scott Bakula praised the Xindi-Arboreals as "quite wonderful." (Star Trek Magazine issue 113, p. 7)