[[File:Labial Pits of P molorus.JPG|thumb|Labial heat pits]]
The rock python's color pattern is whitish or yellowish with the blotched patterns varying from tan to dark brown shades. This varies with terrain and habitat. Specimens from the hill forests of [[Western Ghats]] and [[Assam]] are darker, while those from the [[Deccan Plateau]] and [[Eastern Ghats]] are usually lighter.<ref name="Whitaker">{{cite book |author=Whitaker, R. |year=2006 |title=Common Indian Snakes – A Field Guide |publisher=The Macmillan Company of India Limited |isbn=9781403929556 |edition=revised |pages=6–9}}</ref> All pythons are non-venomous.{{citation needed|date=May 2021}}
The [[nominate subspecies]] occurring in India typically grows to {{convertcvt|3|m|ftin|abbr=on}}.<ref name=Nat.Hist.Soc.1912>{{Cite journal |first=F. |last=Wall |title=A popular treatise on the common Indian snakes – The Indian Python |journal=Journal of the Bombay Natural History Society |volume=21 |year=1912 |pages=[https://archive.org/details/populartreatiseo00wall/page/447 447]–476 |url=https://archive.org/details/populartreatiseo00wall}}</ref><ref name="Whitaker"/> This value is supported by a 1990 study in [[Keoladeo National Park]], where 25% of the python population was {{convertcvt|2.7|-|3.3|m|ftin|abbr=on}} long. Two individuals even measured nearly {{convertcvt|3.6|m|ftin|abbr=on}}.<ref name=Nat.Hist.Soc.1990>{{Cite journal |first=S. |last=Bhupathy |title=Blotch structure in individual identification of the Indian Python (''Python molurus molurus'') and its possible usage in population estimation |journal=Journal of the Bombay Natural History Society |volume=87 |issue=3 |year=1990 |pages=399–404}}</ref>
Because of confusion with the Burmese python, exaggerations, and stretched skins in the past, the maximum length of this subspecies is difficult to tell. The longest scientifically recorded specimen, collected in Pakistan, was {{convertcvt|4.6|m|ftin|abbr=on}} long and weighed {{convertcvt|52|kg|lboz|abbr=on}}. In Pakistan, Indian pythons commonly reach a length of {{convertcvt|2.4|-|3.0|m|ftin|abbr=on}}.<ref name=Minton>{{Cite journal |first=S. A. |last=Minton |title=A contribution to the herpetology of West Pakistan |journal=Bulletin of the American Museum of Natural History |volume=134 |issue=2 |year=1966 |pages=117–118 |hdl=2246/1129 |url=http://digitallibrary.amnh.org/dspace/handle/2246/1129}}</ref>
Differs from [[Burmese python]] (''Python bivittatus'') by the following signs:
