Basically a stink bug, but green and giant one at that. Has fleshy, stout long legs. Tries to avoid the photographer - moves to the other side of the twig. Underside of the trunk has some pores. Length: 25mm. Scale of the size can be guessed by comparing the fly on its tail end.
Damp and bushy area nearby a lake with lots of forests around.
Spotted this giant stink bug, as a bonus (!), while actually looking for some bugs around 'Chaaya Taal', an artificial lake with rainbow trout, some 5km uphill from Hee Gaun in very remote West Sikkim. The family had camped here at a village tourism guest house for angling and nature observation. It was quite fruitful!