This should be fun, I thought, but I never thought I’d have to say that “Mama” was so utterly amusing.

With Guillermo del Toro the executive producer, as he did during “Splice,” a modern horror marvel, I could only think that the funny would be dark; not dumb. You’ll find yourself laughing at “Mama”—the character and the film—while watching director Andres Muschietti’s debut into full-length cinema.

Not all is lost, however, for this film’s savior is Jessica Chastain, making sure the duration isn’t all for naught.