Dan Chupong / Deaw Chupong Changprung is uncredited in Ong Bak 2: The Beginning but he's the guy on the elephant in that poster with Tony Jaa.  And in 6 years, he's gone from his first screen credit as "bodyguard #4" in Ong Bak: Muay Thai Warrior to co-starring in Ong Bak 3.  (Yes, Ong Bak 2 has already opened and Ong Bak 3 is in production in Thailand).  Like Tony Jaa, he started out a member of Panna Rittikrai's Muay Thai Stunt team taking extra parts and after his bit part in Ong Bak has been the lead in Dynamite Warrior (Khon Fai Bin / Konfaibin / Tabunfire) and the 2004 remake of Panna Rittikrai's Born to Fight as well as being featured in Sahamongkol's gargantuan 2008 costume epic/fantasy, Queens of Langkasuka.

His style isn't necessarily as graceful as Tony Jaa's but he's powerful, fast and entertaining to watch while he breaks bad guys' bones and  keeps ramming his knees into their organs.

Here he is in the fight that opens Dynamite Warrior:

 I fear his deadly knees!

Just to get in the mood for historicall asskickery, here's a still from the same film and a poster of his character from Queens of Langkasuka.

Ong Bak 2: The Beginning screens at TIFF on: Saturday September 19, 9:45am -SCOTIABANK THEATRE 2 / Saturday September 19, 11:59pm - RYERSON.