Y'know, looking at this thread kind of intrigues me in consideration to how we look at gender, their roles, and how we view feminine vs masculine traits, or both, or neither.
I knew people who thought Rinkus was a woman, but his voice came off as masculine to me, as I have heard similar voices before in shows like "Pinky and the Brain" and even with Ozzy and Strut within the same series.
In the past I thought Terk and Shenzi were guys, mostly because the majority of females I saw in other media would have traits to distinguish themselves from the guys by having curves, softer features, and paler colorations.