Night of the Howling Beast(1975)

Original title: La maldición de la bestia

Waldemar, the renowned adventurer, joins an expedition to find the Yeti in the Himalayas. While hiking the mountains, he's captured by two cannibalistic demon nymphets guarding a remote Buddhist temple and becomes their sex-slave. They transform him into a werewolf setting him loose to roam the mountain where he encounters a sadistic bandit.