Chalcorana megalonesa — Large White-lipped Frog
Some other names for this species:
White-lipped Stream Frog
Chalcorana megalonesa is one of several similar-looking species split from the Rana "chalconata" species complex. It differs from Chalcorana raniceps primarily in size.
My not completely reliable memory tells me that this specimen was large enough that it must have been Chalcorana megalonesa rather than Chalcorana raniceps, but I wouldn't place a large bet on that.
This was a big 'un, and my understanding is that the lack of green on the back is also a pretty good indicator that this is C. megalonesa rather than C. raniceps.
- Inger, R. F., Stuebing, R. B., Grafe, T. U., Dehling, J. M. 2017. A Field Guide to the Frogs of Borneo, Third Edition