Tony Leung Ka-fai

as Inspector Tang

Joyce Ni Shu-Chun

Bennett Pang Kin-San

as Fire Unicorn

Tai Bo

as Tai Bo

Charlie Cho Cha-Lee

as Charles

Chong Man-Ching

as Mrs. Cow

Tsang Dao-may

Hon Yee-Sang

as Tang's assistant

Christopher Durkin

as Inspector Caine

David Wu

Lee Hoi-Sang

Jamie Luk Kim-Ming

as Man in toilet

Wu Chia-Hsiang

as Cleaner at police station

Terry Tong Gei-Ming

Alan Chan Kwok-Kuen

as Mr. Cow

Yen Li

Johnny Lee Man-Yiu

Pan Yung-Sheng

as Golden Mouse

Yat Boon-Chai

Yu Miu-Lin

Tsang Choh-Lam

as Opium smoker detained at station

Fung Ging-Man

Anna Ng

as Fa Dan Chun

Johnathan Chow Chun-Tung

Bruce Mang

Cheung Lin-Ping

as Policeman

Eddie Chan Shu-Chi

Billy Lau Nam-Kwong

Stuart Yung Sai-Kit