This peculiar looking lizard, spotted by Jess in Mulu, is a Black-barbed Flying Dragon (Draco melanopogon). As well as seeing it on this tree where it scampered about rather quickly, some of us saw another individual gliding overhead (at least 30m) when we were waiting for the bats to emerge from Deer Cave.

Flying lizards fly by stretching out the skin down their flanks (kind of like Chitty Chitty Bang Bang.