They are the only alien muppets that arrive on Sesame Street.
They are "yip-yipped" by multiple muppeteers like Jim Henson, Frank Oz and Martin P. Robinson.
... American, 0.04% Native American, 1.49% Asian, 0.00% Pacific Islander, 1.08% from other races, and 1.08% from two or more races. 6.61% of the population are Hispanic or ...