I'd never be able to tell whether this was Gonocephalus borneensis or Gonocephalus liogaster from this photo, or possibly from any number of photos, because the species are very similar and the babies in particular are close to indistinguishable. But the adults I saw nearby on the next few nights were clearly G. borneensis, and I subscribe to the theory that these two species are not sympatric (that is, don't live in the very same places). But I'd love to be proven wrong.

Adult male Gonocephalus liogaster have those gorgeous baby blue eyes, but Gonocephalus borneensis have such wonderfully sloppy crests! I know who I would pick in a fight. (Good thing for the G. liogaster that they probably aren't sympatric!)

This one is definitely a ruffian, and had some sort of disagreement earlier. You should see the other guy.

Danum Valley offered up a kaleidoscope of Gonocephalus borneensis. I'm not sure whether different individuals are different colors, or whether each individual can change from one color to the next based on mood, temperature, etc. Probably the latter, but I haven't found any written confirmation. Lizards of Borneo just says that they are "bright green", but that is clearly not always the case.

I saw a few orange-ish individuals, of which this was the most orange. I believe the crest is large enough to mark it as another adult male, so the color differences don't seem to be related to gender.

(Auto-correct kept changing "orange-ish" to "orange-fish", which is fun but unhelpful.)

A couple of the more standard greenish flavor. I believe the top one is an adult male (tall crest), and the second one is an adult female (large size, but relatively crest).

I saw a couple dozen of these lizards in a few days in Danum Valley. The majority were resting at night, but I saw quite a few during the day as well. This was one of the more attractively patterned individuals. I think this is an adult female.