Sprocket is the name of the dog on Fraggle Rock who was puppeteered by Steve Whitmire and assisted by Karen Prell.

Sprocket was Doc's dog, he has the intelligence of a human and can communicate with Doc.

From Webster's:

sprock·et
noun

1 : a toothed wheel whose teeth engage the links of a chain
2 : a cylinder with teeth around the circumference at either end that project through perforations in something (as motion-picture film) to move it through a mechanism (as a projector)

Sprock"et (?), n. [Etymology uncertain.] (Mach.)

(a)

A tooth or projection, as on the periphery of a wheel, shaped so as to engage with a chain.

(b)

A sprocket wheel.

 

© Webster 1913