Coastal taipan venomous snake in Australia. Adult specimens of this species typically attain sexual maturity around in total length (including tail). More mature specimens can grow to between . Other taipans, including the inland taipan, attain broadly similar sizes although they tend to be slightly smaller in average size. A specimen of an average total length weighs around . According to the Queensland Museum, the longest recorded total length for the coastal taipan was a specimen that was and weighed . However, though exceptionally rare, much larger specimens are widely believed to exist, including specimens of as much as . The taipan
Coastal taipan is exceeded in length among venomous snakes only by the Asiatic king cobra, African black mamba, and genus "Lachesis" (bushmasters) of the American neotropics. The head of the coastal taipan is long and narrow like that of the African black mamba ("Dendroaspis polylepis"), but without the "coffin" shape. The two species are strongly convergent in several aspects of morphology, ecology and behaviour. "O. scutellatus" has an angular brow and is lighter-coloured on the face. The body is slender and colouration can vary. It is often uniformly light olive or reddish-brown in colour, but some specimens may be dark gray to