Boyd's forest dragon is generally brown or grey above, with some individuals having a green flush. The body is laterally compressed. It has very enlarged cheek scales, a prominent
nuchal crest, and a yellow
dewlap under the chin that is edged with enlarged spines. The
tympanum is large and superficial. A
dorsal crest, discontinuous with the nuchal crest, consisting of enlarged, hardened and pointed scales, runs down to the base of the tail. Adults are
sexually dimorphic, with males larger than females and having larger, blockier heads. Adult males grow to an average body length (snout-vent length) of about , with the tail adding another ; average body length for adult females is about and tail length is about . Average body mass for adult males is about , and for females is about . ==Behavior==