The birds of the genus Celeus generally weigh between 63–172 g (2.2–6.1 oz); the heaviest of this genus is the  scaly-breasted woodpecker  (C. grammicus).
Length, from tip of bill to tip of the tail, is between 19–32 cm (7.5–12.6 in).
They are generally not sexually dimorphic and have evolved specialised  morphology to match their unique lifestyle.

The beak differs from other woodpeckers  in that it is mainly curved, not long and without nostril feathers.
 Like other woodpeckers  its beak has a chisel like cutting edge.
 A hard rhamphotheca and complex beak microstructures strengthen the bill for pounding and drilling.
The tail has evolved for support, clinging and climbing, acting as a third leg or tripod.
 The pygostyle (tail vertebrae) is larger for strong tail muscles to be inserted and it is more or less stiff.
 There are six pairs of tail feathers, the middle feathers of which have strong central shafts for extra support.
The feet are zygodactyl, with scansorial abilities, and therefore adapted to climbing vertical surfaces, however, they are not as specialised as other woodpeckers for this purpose.
 The first toe is short, the 4th toe being shorter or of equal length to remaining two toes.
 Most species in this genus use a bipedal hopping movement on vertical and horizontal surfaces.
Claws have evolved for climbing.

Celeus species use their tongue to capture food.
 The tongue is long and capable of lateral movements.
 Due to its length the tongue does not have the usual tongue retractor muscle found in most birds, instead, there is an elongated tongue muscle (the Branchiomandibularis) along with bones of the hyoid horn, which provide increased tongue protraction.
 Retraction of this long tongue may find it wrapped around an eye socket between the skull and the skin.

Head crests are bushy, shaggy or peaked in typical woodpecker style and, along with flight and body feathers, are chestnut colours of brown, black and cream (some almost yellow).
 There is a greater or lesser degree of  barring (bars or stripes of feather colour) and sexual dimorphism badges are mainly between the bill, eye and chin of males.
These sexual badges are usually red.
 The oil gland is particularly large in this genus.
 Plumage convergence has been noted in divergent lineages possibly as a form of territorial mimicry but no real conclusions have been made as yet.
The birds of the genus Celeus generally weigh between 63–172 g (2.2–6.1 oz); the heaviest of this genus is the  scaly-breasted woodpecker  (C. grammicus). Length, from tip of bill to tip of the tail, is between 19–32 cm (7.5–12.6 in). They are generally not sexually dimorphic and have evolved specialised  morphology to match their unique lifestyle.
The beak differs from other woodpeckers  in that it is mainly curved, not long and without nostril feathers.  Like other woodpeckers  its beak has a chisel like cutting edge.  A hard rhamphotheca and complex beak microstructures strengthen the bill for pounding and drilling. The tail has evolved for support, clinging and climbing, acting as a third leg or tripod.  The pygostyle (tail vertebrae) is larger for strong tail muscles to be inserted and it is more or less stiff.  There are six pairs of tail feathers, the middle feathers of which have strong central shafts for extra support. The feet are zygodactyl, with scansorial abilities, and therefore adapted to climbing vertical surfaces, however, they are not as specialised as other woodpeckers for this purpose.  The first toe is short, the 4th toe being shorter or of equal length to remaining two toes.  Most species in this genus use a bipedal hopping movement on vertical and horizontal surfaces. Claws have evolved for climbing.
Celeus species use their tongue to capture food.  The tongue is long and capable of lateral movements.  Due to its length the tongue does not have the usual tongue retractor muscle found in most birds, instead, there is an elongated tongue muscle (the Branchiomandibularis) along with bones of the hyoid horn, which provide increased tongue protraction.  Retraction of this long tongue may find it wrapped around an eye socket between the skull and the skin.
Head crests are bushy, shaggy or peaked in typical woodpecker style and, along with flight and body feathers, are chestnut colours of brown, black and cream (some almost yellow).  There is a greater or lesser degree of  barring (bars or stripes of feather colour) and sexual dimorphism badges are mainly between the bill, eye and chin of males. These sexual badges are usually red.  The oil gland is particularly large in this genus.  Plumage convergence has been noted in divergent lineages possibly as a form of territorial mimicry but no real conclusions have been made as yet.
Celeus (bird)