Brilliant puppetry and an enigmatic, wickedly funny tale of obsessive love and murder most foul are combined in ''The Repugnant Story of Clotario Demoniax,'' which opened the International Festival of Puppet Theater on Tuesday night at the Joseph Papp Public Theater.

As presented, partly in Spanish but mostly in English, by the Mexican troupe Teatro Tinglado under the direction of Pablo Cueto, this meandering story by Hugo Hiriart about the gleefully lethal villain Clotario and the sometimes brutal mysteries of life unfolds by means of puppet and human performers.

There are tiny puppets that emerge from a suitcase. There are small and medium-size versions of the principals seen in the type of puppet theater familiar to patrons of Punch and Judy shows. There are human actors who play out their roles alongside their puppet counterparts, and, occasionally, there are half-human, half-puppet characters.

The principal story focuses on the brilliant, evil Clotario, a white-faced, toothy version of Punch who begins the proceedings by murdering a friend on a snowy mountainside because Clotario yearns for the poor fellow's fiancee. (When heads roll in this show, they really do.) At the wake, complete with tiny coffin and sobbing, wailing mourners, the devious Clotario tells the bereaved fiancee that the dying wish of her beloved was that Clotario marry her.

On their wedding night, in a wild, funny digression into striptease, the frustrated Clotario is forced to tell a series of stories involving a whole new set of puppet characters in exchange for pieces of his reluctant bride's clothing. And when Clotario unintentionally conjures up a huge genie who makes his wife disappear, ''The Repugnant Story of Clotario Demoniax'' moves through a slow, satiric radio talk show about a woman's quest for a husband to its inconclusive showdown in the lair of the evil Queen of the Tabloids, where Clotario has tracked his long-suffering wife.

For all its foul deeds and nasty characters, ''The Repugnant Story of Clotario Demoniax'' is packed with imagination, invention and, best of all, humor. When puppets are involved, a few extra whacks with a red cloth club during a murder seem funny. Puppet characters bounce on the springs of a bed, do double-takes and literally lose their heads. In a knock-down, drag-out fight, a tiny puppet refreshes herself at the artificial breast of her human counterpart, and a bell tinkles to signal the resumption of lethal combat.

The talented humans in the show are Ramon Barragan, Haydee Boetto, Aejandro Benitez and Mr. Cueto. Performances of ''The Repugnant Story of Clotario Demoniax'' are scheduled for today and Friday at 7:30 P.M., Saturday at 3 and 6 P.M. and Sunday at 2 (in Spanish) and 5 P.M.

THE REPUGNANT STORY OF CLOTARIO DEMONIAX

By Hugo Hiriart; directed by Pablo Cueto; puppets by Mireya Cueto and Mr. Cueto; sets by Mr. Cueto; costumes by Erica Cerdeno-Lance. International Festival of Puppet Theater. Teatro Tinglado, Mexico, presented by the Jim Henson Foundation. At the Public Theater, 425 Lafayette Street, East Village.

WITH: Ramon Barragan, Haydee Boetto, Pablo Cueto and Aejandro Benitez.

Photo: Ramon Barragan, left, and Aejandro Benitez playing half-human, half-puppet characters in ''The Repugnant Story of Clotario Demoniax.'' (Tom Brazil)