Abbie Cornish, Olga Kurylenko, Zeljko Ivanek, Gabourey Sidibe and a bunny petting Tom Waits also star.
Martin McDonagh, who earned acclaim for his 2008 film "In Burges" (also starring Farrell), wrote and directed "Seven Psychopaths."
Based on the reaction the trailer is getting, it's clear the film is generating considerable buzz.
"We've been anxiously awaiting director Martin McDonagh's follow-up to his 2008 debut feature "In Bruges" seemingly since it was announced, and everything new we find out about it further cements that interest," says MTV's Terry Schwartz. This latest trailer teases everything we'd hoped would be in "Seven Psychopaths": fantastic writing, great comedic elements, chemistry between the cast and a whole lot of Colin Farrell."
Hollywood.com's Michael Arbeiter notes that "Seven Psychopaths" could mark somewhat of a comeback for Walken.
"People forget that Walken once put a gun to his head in a Vietnam basement, delivering one of the most powerful big screen performances in the history of cinema (that would be from 'The Deer Hunter')," says Arbeiter. "Instead, talks of Walken are generally limited to recitations of his 'Pulp Fiction' speech and 'More cowbell!'" sketch lines. Once the world realized how funny Walken could be, that's all it wanted from him. The past decade has placed the actor primarily in cameo roles playing 'weirdos.' 'Seven Psychopaths' is a comedy, and a wacky one. But it looks like it might actually use Walken for more than a one-trick pony."
Lee Hernandez of Celebuzz believes that the film could grant Harrelson awards season recognition.
"Harrelson, a two-time Oscar nominee for 'The People vs. Larry Flynt' (1997) and 'The Messenger' (2010), looks Oscar-worthy as Charlie, a hardened criminal with a surprising soft spot for his furry-faced pup."
The film is set to screen at the Toronto Film Festival Sept. 7. and is slated to hit theaters Oct. 12.