The toughest, gristliest meat I've ever eaten was armadillo. It does not taste like chicken.
Neither does anything else, except chicken. Rattlesnake most certainly does not, but it is often described that way. It has a funny 'reptilian' taste, and the meat has a different texture. It's also difficult to eat; I recomment a scalpel and a pair of pliers, rather than a knife and fork.
I've eaten snake, beaver, alligator, frog, cicada, grasshopper, cow brain (before I had heard of mad cow disease...) and numerous other 'different' foodstuffs. I can't even fathom eating armadillo. What in the world prompted that?