Pseudobufo subasper occurs in Malay Peninsula, Borneo, and Sumatra.
The species has pronounced aquatic habits and lives in close association with pools in coastal peat swamps. On the Island of Borneo it has been reported for Kalimantan.
The toads are large: up to 94 mm in males and 155 mm in females (snout-vent lengths). The dorsum is brown to dark grey. There is a light lateral stripe and a medial dorsal stripe may be present. The toad is covered densely with warts. The head is moderately broad (compared to some other toads).
Its aquatic life-style, lethargic habits and camouflage coloration make it difficult to find these toads (Inger & Stuebing 2005). Especially on Borneo where their distribution seems to be restricted. These toads are more easily seen in some parts of the Malay Peninsula.
Males are distinguished from females by their black throat.