Changeable Lizard or Oriental Garden Lizard

It is usually streaky brown. It has the ability to camouflage itself so seems to have appropriated the colours of the moss-covered walls. It has a crest which can be quite prominently visible at times. Sometimes it makes a bobbing movement with its head which may be a threat display.
In Delhi I have seen an individual with a red head which is what males get during the breeding season...perhaps a reason why in my childhood we called them Rokto (blood)-chosha (sucker) = Blood-sucker.