The little green men were the creatures who controlled the Lefty robot.
During the short "Lefty" of Dipper's Guide to the Unexplained, they control the Lefty robot, so it can only be seen from the left side so no one would find out about them. During the third test, when Dipper tries to see the Lefty Robot's right side, he finds the little men controlling it.
Upon discovery, they swallow small, glowing, red cubic pills, while yeling "the time has come!" They subsequently collapse one by one and vanish in flashes of red light. One of them says that he can't fulfill the pact because "[he has] a family", to which his partner replies "you took the oath!" Then they also commit suicide by swallowing the red cubes, falling out of the robot, and then disappearing after they die. The robot then self-destructs.
They are small cylindrical and gelatinous green creatures, with a round top and two humanoid arms. Thay wear black gloves and a black belt with a lightning bolt on the buckle. They have relatively large eyes with red pupils and prominent dark green lips.
- 4. "Lefty"
"We're blown, shut it down! Shut it down!"
"- The time has come, brother!
- There are a total of 16 creatures shown in the short.