[3] The specific name, macmahonii (or macmahoni ), is in honor of British diplomat Arthur Henry McMahon.

[4] E. macmahonii is a relatively small species growing to a total length (including tail) of less than 1 m (39 in).

[2] The body is dorsoventrally slightly depressed and appears moderately to markedly stout.

The dorsal scales are short and keeled, in 23-29 midbody rows that are arranged in a straight and regular pattern.

The head has a white stripe that runs from the back of the eye to the angle of the mouth.

[1] According to Mallow et al. (2003), this species is reported from Pakistan, Afghanistan, eastern and northwestern Baluchistan, southern Iran, and India in the Rajasthan Desert.

It is limited to the Dast-i Margo Desert and nearby dune areas, from Seistan in the extreme east of Iran into Afghanistan south of the Helmand River.

It also occurs in Baluchistan, between the Chagai Hills and Siahan Range, east to Nushki.

[2] Eristicophis macmahonii is associated with (shifting) dune habitats of fine, loose sand.

It will raise the front part of its body off the ground in a loop and strike aggressively.

[2] Eristicophis macmahoni can appear to sink down into the sand using a rocking or peristaltic motion.