The 19-year-old impressed during a two-week trial at Vicarage Road and has been given a two-and-a-half year contract by the Hornets.

Ashikodi started his career at Millwall before joining West Ham in 2004. He moved to Rangers in January 2006 but did not start a first-team game there.

He has represented England at all levels from Under-15 to Under-19.

Ashikodi will go straight into the Hornets' squad for Saturday's FA Cup tie against Stockport.