H. pealii may attain a total length of 50 cm (19 inches), which includes a tail 12.5 cm (4 inches) long.
Dorsally, it is dark brown. On each side are two light stripes, an upper narrow one, and a broader lower one, which is two scales wide. The top of the head is dark brown. The
rostral, the upper
labials, and the lower labials are yellow, blotched and edged with brown. The
ventrals are very dark brown, marked with light yellow laterally. There is also a faint yellow stripe along the center of the ventrals, which becomes more distinct posteriorly. The
dorsal scales are strongly keeled (less strongly in the outermost row), and arranged in 19 rows at midbody. Ventrals 142-144; anal plate entire; subcaudals 75-77, divided. ==Reproduction==