The Gasguzzler 9000 is described being a bronze colored ship with a one eyed bull skull, and a green tank that the parasite sits in. In the tank is a leopard-skin seat cushion, pink fuzzy dice, and a pine tree air freshener. It does not appear to be very eco-friendly, due to the grey masses of smoke it emits and its name. This reflects the intention of the parasite.
The Gasguzzler 9000 does not play a big role in Parasite. It is seen at the start and end of levels. At the start, the parasite drives the vehicle to where he wants to start the level, and then then jumps out of it. The Gasguzzler will then fly off, and fly over to the area the Parasite ate the last big forest spirit in the area.
The parasite will then jump back into the Gasguzzler, and fly off to his next destination. The Gasguzzler is used by the parasite for travel between planets, and around planets. Hence its name, it probably consumes massive amounts of gas. The Gasguzzler serves only as transportation between levels, and really nothing else, as it cannot be interacted with during gameplay.