Naja philippinensis was described by American herpetologist Edward Harrison Taylor in 1922. The generic name naja is a Latinisation of the Sanskrit word nāgá (नाग) meaning "cobra". The specific epithet philippinensis is Latin and literally means "from the Philippine Islands".
The Philippine cobra is a stocky snake of medium length with long cervical ribs capable of expanding, so when threatened, a hood can be formed. The average length of this species is 1.0 metre (3.3 ft). The species can grow to lengths of 1.6 metres (5.2 ft) However, subpopulations of the species, particularly specimens from Mindoro Island, are said to attain lengths of 2 metres (6.6 ft), but these are unconfirmed claims. If true, however, 2 m would be very rare and would be considered the absolute maximum for this species. The head is elliptical, depressed, slightly distinct from neck with a short, rounded snout and large nostrils. The eyes are moderate in size with dark brown and round pupils, typical of other cobra species and similar to other elapids in general. It has a fairly stocky build for an elapid, and adult snakes are uniformly light to medium brown, while the juveniles tend to be a darker brown in color. They have 23-27 scale rows around the neck and 21 just above the middle part of the body; 182-193 ventrals, 36-49 subcaudals, and basal pairs are sometimes undivided.
The Philippine cobra occurs mostly in the northern regions of the Philippines. They can be found on the islands of Luzon, Mindoro, Catanduanes, Azria and Masbate. This species likely may occur in other neighboring islands, but this remains unconfirmed. Records from the Calamianes group and Palawan require confirmation.
The Philippine cobra’s habitat include low-lying plains and forested regions, along with open fields, grasslands, dense jungle, agricultural fields, and human settlements. This species of cobra is particularly fond of water, so it can be found very close to ponds, rivers, or large puddles of water.