Trimeresurus nebularis, or the Cameron Highlands Pit Viper is a species under the family Viperidae, subfamily Crotalinae (pit vipers). The Cameron Highlands Pit Viper was first described in 2004 and is found in the mountain ranges south of Pahang, at elevation of around 1500 m. This species was subsequently discovered at Fraser’s Hill, 100 km away to the south of the Cameron Highlands. The southernmost encounter of this species was at Genting Highlands (an unreported bite incident). It has been found at elevation ranging from 1000 to 1500 m and is mainly distributed along the central part of the Titiwangsa mountain range, and has been more recently found in southern Thailand (Das, 2012).

Trimeresurus nebularis males can attain about 100 cm, while females reach at least 95 cm. It has a robust and cylindrical body, the head and the neck can easily be distinguished; it’s pupil is vertical within a yellowish green or green iris. The body dorsum is bright green, with a hint of blue. The upper labials scales are usually bluish-green, while the throat and chin are yellowish green. Ventrolateral stripe and postocular streak are typically absent. The tail is green laterally and its vertebral region rusty brown, with a sharp line in between (Sumontha et al., 2011). Birds and small mammals are likely to be part of its diet (Wong, 2018).

Trimeresurus nebularis is venomous and its bite can potentially cause coagulopathy (bleeding disorder) in humans. It is listed as Vulnerable (VU) under the IUCN Red List of Threatened Species, due to its limited distribution, reaching a maximum of roughly 6,600 km² area in central highlands of Peninsular Malaysia (Grismer, 2012).