Douglas Ma'afu Hawke, better known as Doug "Vicious" Viney (born 20 November 1976) is a Tongan-New Zealander heavyweight boxer and kickboxer.

He is the K-1 World GP 2007 in Las Vegas champion, who also represented Tonga as a super heavyweight boxer under the name of Ma'afu Hawke at 2004 Summer Olympics in Athens, Greece.

He knocked out Dion Crouch and Auckland Aumitagi in the quarter and semi-finals, respectively, before going on to face Rony Sefo in the final, who he defeated via decision.

He then went on to the K-1 World Grand Prix 2002 Preliminary Melbourne in February 2002, where he was defeated in the semi-finals by Andrew Peck after beating Chris Chrisopoulides in the quarters.

After defeating Mahmoud Fawzy in the reserve match, he was called in to the semi-finals to face Aleksandr Pitchkounov after Rick Cheek pulled out of the tournament with an injury.