Credit to T.Laurent on airliners.net here.
Thai Lion Air is a Thai low-cost airline based in Bangkok’s Don Mueang airport. They operate domestic flights in Thailand and international flights within Asia.
Thai Lion Air was founded on the 4th of December, 2013 and operated their first flight, a Bangkok - Chiang Mai flight on the same day.
Currently their fleet consists of 10 737-800s, 17 737-900ERs and 3 A330-300s.
The first A330 was delivered late last year and was registered HS-LAH.
Unlike a lot of livery requests currently, this isn’t for a CRJ!