The Great Myna (Acridotheres grandis) looks very similar to the Javan Myna (Acridotheres javanicus) but is slightly larger.
The Great Myna is 24-25 cm whereas the Javan Myna is 21-22 cm.
The Great Myna is found in Northeast India, through Bangladesh to Southeast Asia whereas the Javan Myna used to be endemic to Java and Bali but has been introduced in other parts of South East Asia (like Singapore).

In the company of the slightly smaller Common Myna (Acridotheres tristis).

Lumphinipark, Bangkok, Thailand, 19 January 2013