Robert Downey Jr. The trio of stars talk about about reaching the heart of darkness — and ridiculousness! — on the set of their jungle-set action comedy. Jackson, Eric Winzenried. Jackson, Jay Baruchel, Danny R. Starring Ben Stiller, Robert Downey Jr. [HOST]: Tropic Thunder: Ben Stiller, Jack Black, Robert Downey Jr. When production on a fictional film about the Vietnam War stalls due to the antics of its spoiled. lead an ensemble cast in "Tropic Thunder," an action comedy about a group of self-absorbed actors who set out. Ben Stiller, Jack Black and Robert Downey Jr. , and Jack Black. lead an ensemble cast in 'Tropic Thunder', an action comedy about a group of self-absorbed actors who set out to. Jack Black having his belly drawn on by Robert Downey Jr! Ben Stiller, Jack Black and Robert Downey Jr. Tropic Thunder () - Robert Downey Jr. . - Jack Black - Ben Stiller - Comedy - Action - LRC Watch Party: Con La Reina Creole, Retro Nerd Girl, Rrr Mmm. , Jeff Kahn, Anthony Ruivivar, Jay Baruchel, Brandon T. , Brandon T. McBride, and Nick Nolte. the strengths brought to the project by Ben Stiller, Jack Black, Robert Downey, Jr.