The 27-year-old singer was filming the clip for 'GUY (Girl Under You)' in California when the creature, an endangered species, sunk its teeth into her, reported Contactmusic.
"The slow loris is the cutest creature on the planet, and Lady Gaga wanted to use it in one scene, but it nipped her. They put it back in its box and took it away in disgrace," a source said.
But Gaga is apparently unhurt after the incident.
"She just laughed about it," the source added.