Hmm, well Cera had moments that seemed considerably evil, like when she would tell Littlefoot in Episode 5, when she would pester him about being friends with Chomper and make fun of Chomper saying he would eat Littlefoot 
I can't believe I missed this thread for a while, but I would argue that Cera doesn't come off as evil, just mean-spirited at her worst moments. In the first film, she's definitely a foil to the extent of being an antagonist, but she isn't outright malicious more so confused. Just because one is actually counterinituitve to the situation does not make them evil, per-se, it's all about perspective and the big picture.
We are meant to view Sharpteeth as svil through the eyes of the Gang of Five. However, Chomper and his parents allowed us to have a more objective view of Sharpteeth considering, seeing them less as villians and more as simply meat eaters.
This as well. From a prey's point of view, sharpteeth are monsters, but as Chomper proved, this is also a two-dimensional theory. Thud wouldn't have done what he did in the TV series in that one episode if he was a complete monster, for instance. This pretty much discounts most, if not all sharpteeth, since by Circle of Life aesop propagated by the first movie implies that such chases are just the natural order of things, even if the gang must detest it and view sharpteeth as horrible enemies. Again, subjectively based on the lens/POV.
Definitely Ozzy, Rinkus, and Sierra as they are shown to have no qualms with killing for the sake of killing.
I'll probably join the consensus for this as well. Maybe less so Ozzy, as by the end of LBT2 the tormented eggstealer is completely and utterly frustrated to the point of snapping, but both Rinkus and Sierra gave off a very sinister vibe through their film even if the final payoff at the climax wasn't so cathartic.
...although some people from this forum hold the opinion that a certain smug green-eyed longneck from the TV series is the single most evil antagonist the series has ever produced.
