Following up on Rod, here is the complete set, to which your stamp belongs:

The stamps were issued in 1931, printed in Hyderabad from plates engraved in London. They were also overprinted in Persian 'SARKARI' meaning 'government' for official use, like your example.
These stamps were very heavily used, and values like your 4 Pies stamp were printed many times, producing a range of shades

and on two types of paper: ordinary watermarked paper and laid paper.
The rulers of Hyderabad were Muslim (although most of the population were Hindu) and, as Rod said, avoided showing living things on their stamps for religious reasons (the Biblical Second Commandment, which Muslims also follow). Hyderabad only slipped up once, for the 1945 Victory commemorative

which shows a soldier from the Hyderabad contingent of the Indian Army returning to his wife and child.