This is a pictograph of a dog. The dog's body posture, standing tall, with a straight-up tail and rigid legs, tell us that he sees something as a threat. The slightest provocation may cause the dog to attack. Therefore, this Indus sign is the noun dog or guard dog.
Illustrative Text Reference:
Ur: Stamp seal: Museum Number 122847: British Museum Collection Online: http://www.britishmuseum.org/research/collection_online/collection_object_details.aspx?objectId=805148&partId=1&searchText=indus+seal&page=1: Accessed: 27 October 2018.
Comments:
There is only one extant example of this Indus sign.
In the inscription from Ur, it is interesting to note that the guard dog sign is preceded by a row of six teeth, which represent canine incisors.
Image Credit:
Indus Script Sign Number 9832: List of Sign Variants: Iravatham Mahadevan, 1977: The Indus Script: Texts, Concordance and Tables: The Director General Archaeological Survey of India.