So I've had the idea for a while that I wanted to bring back Garrus' taur form in some way. He has a mershark for aquatic conditions, a roo form for on the ground where bipedal forms are more suited, a naga form for handling situations that require larger builds and well, I guess this came about as an unexpected land traversing form possibly suited best for a more aggressive existence.

Garrus always found that his body seemed to undergo a process of heavily expedited evolution, only stopping with the end result being an easily shapeshiftable form that mostly held its shape and didn't make him feel he was going to collapse into a formless liquid at the slightest moment of losing his concentration on his currently taken shifted form. Builds or forms in which he guessed his body "accepted" that were not necessarily his own choice, 99% of the time.

It may well be something to do with his symbiotic body's reach into the genetic information of his hosts, the realisation of the environment around him and the host's species, if native or well suited, has sway in the forms he takes. That, and the somewhat unpredictable additions he finds himself with such as extra arms, cocktongues or in this case, a pair of lower bodies.

Now, before you ask or comment, he isn't stuck with two lower bodies facing front to front, it's just the angle. He walks with both parallel to eachother and they don't really rub or chafe, the "necks" that his upper body connects to each with has some stretch and room.
He keeps his pouch between forms the same way his mouth tends to remain completely absent between them too.

Art by the amazing  skdaffle <3