It consisted of a small central core containing the drive system and three extended wing-like sections extending forward, mounted at 120 degree angles along the fore-aft axis. The ships were heavily armed with pulse-firing particle cannons and torpedoes. They were also highly decentralized in layout, possessing no central control room, reflecting the non-hierarchical nature of Insectoid culture. There was at least one room that had a viewscreen for communications. (ENT: "Countdown")
In early 2154, Enterprise NX-01 discovered the wreckage of a crashed Insectoid ship while traveling to the Azati Prime system. The Enterprise crew discovered that the adult crew had died when they transferred power from life support to power the on-board hatchery, protecting their young. (ENT: "Hatchery")
In an alternate timeline in which the weapon was successful in destroying Earth, ships of this type were part of a Xindi assault fleet sent to destroy the last remnants of Humanity in the Ceti Alpha system in 2165. (ENT: "Twilight")
Despite being introduced in the episode "Twilight", the final draft script for that episode gives no physical description of this type of craft.
The exterior of the "Xindi-Insectoid starship" was designed by John Eaves, who hit upon the design idea after he had a lobster dinner. "I got the assignment the next day to start working on the Xindi Insectizoid ship," said Eaves. "Having those big buttery crab legs still on my mind, my subconscious mind doodled out the starship version of my dinner!!!! I was very happy with the first pass of this flying seafood dinner starship and so was my boss, Herman Z. We drew up a couple of size charts and off it went to Mr. Berman's office…the drawing came back with a hard line through the middle of the legs that translated out to be, 'cut em off here,' so the next version featured a shorter version which got the approval in red ink and an actual written note!!! WOW, that didn't happen too often!!!" 
Approved on 2 October 2003, the design was sent over to Eden FX, where Pierre Drolet built and rendered the design as a CGI model. During the build, Drolet had to make some adjustments, as he was mistaken about the flight direction of the ship. Eaves was pleased about Drolet's input, regarding the central core. "I love how he split the central core of the ship into two segments," Eaves remarked, "instead of a symmetrical three piece section to match the three extrusions." 
Star Trek: Enterprise's art department designed the interiors of Xindi-Insectoid vessels by taking a cue from the fact the Insectoids themselves were imagined as requiring dark and moist environments. Production designer Herman Zimmerman said of the interiors, "We made three separate vacu-form [wall panel]s, brand new, for the Insectoids [...] even though we only saw environments for them twice – the inside of a control section for the ship, which was really a viewscreen shot ['Countdown'], and then the corridors and 'Hatchery'." (Star Trek: Communicator issue 151, p. 56) In the final draft script for "Countdown", the control area is described as simply "a one-wall set."
In the Bethesda Softworks game Star Trek: Encounters, the Xindi-Insectoid ship was used for the "Xindi fighter", albeit rotated 180 degrees. It also appeared in the game Star Trek: Conquest, where it was identified as a Xindi scout.