This is a pictograph of a kalij pheasant. Key identifiers for this bird are the crest, and the shape of the tail.
Illustrative Text Reference:
Mohenjo-daro: Seal: M-1831 a: Asko Parpola, B. M. Pande, and Petteri Koskikallio, 2010: Corpus of Indus Seals and Inscriptions: Volume 3,1: Page 57: New material, untraced objects, and collections outside India and Pakistan: Suomalainen Tiedeakatemia.
Comment:
Unfortunately, there is no photograph of the seal itself in Parpola's corpus. There is only a poor quality image of the sealing. It is therefore, impossible to conclude whether Mahadevan's portrayal of the crest on the pheasant matches that of the original seal.
Image Credit:
Indus Script Sign Number 1207: List of Sign Variants: Iravatham Mahadevan, 1977: The Indus Script: Texts, Concordance and Tables: The Director General Archaeological Survey of India.