Stark Mad is a 1929 American pre-Code adventure film produced and distributed by Warner Bros., directed by Lloyd Bacon, and starring H. B. Warner, Louise Fazenda, Jacqueline Logan and Henry B. Walthall.

[1] James Rutherford has organized an expedition to the jungles of Central America to find his missing son, Bob, and his guide, Simpson.

Professor Dangerfield intercepts the party, bringing with him Simpson, whose experiences in the jungle have made him a raving maniac.

After Bob's fiancée Irene disappears, they come across a large ape chained to the temple floor, and Captain Rhodes, commander of the yacht, is abducted by a strange monster with great hairy talons.

Simpson's sanity returns, and he saves the party, revealing in flashback that he had lost his mind after murdering an old demented hermit who had been living in the ruins, because the fiend had murdered Rutherford's son Bob two months before.