The most notable feature of this extraordinary looking primate is its enormous eyes (2); tarsiers have the biggest eyes relative to their body weight of any mammal (4). As well as huge eyes, the Philippine tarsier has large, membranous ears set on its rounded head. It has short forelimbs, but greatly elongated hindlimbs, a feature which is reflected in this species name as tarsier refers to the elongated tarsal or ankle region (2). Its long digits culminate in rounded pads that provide the tarsier with effective grip on any surface. The fully opposable first toes also help the tarsier grip to slender branches (2). All the fingers and toes have flattened nails, except for the second and third toes which have claw-like nails used in grooming (2). The Philippine tarsier has wavy fur with a silky texture, ranging in colour on the upperparts from buff or greyish-brown to dark brown. The fur on the underparts is buff, greyish or slate (2). The tail is naked apart from a few short hairs on the tip, and is used as an extra support when clinging to an upright branch (2).