flying squirrel
鼯 refers specifically to the flying squirrel, a type of rodent known for gliding between trees.
鼯 is a phono-semantic compound: the left radical 鼠 (rat, mouse) indicates the animal, and the right component 吾 likely provides the sound. The exact historical development is uncertain.
The left side 鼠 means rat or mouse, and the right side 吾 looks like a stretched-out shape. Imagine a mouse with a cape-like membrane gliding through the air: a flying squirrel.
For ゴ, picture a flying squirrel going from tree to tree: go -> ゴ, as it glides away.
southern flying squirrel (Glaucomys volans)
feathertail possum (Distoechurus pennatus); feather-tailed possum
northern flying squirrel (Glaucomys sabrinus)
yellow-bellied glider (Petaurus australis)
Siberian flying squirrel (Pteromys volans)
squirrel glider (Petaurus norfolcensis)
feather-tailed glider (Acrobates pygmaeus); feathertail glider; flying mouse; pygmy gliding possum
Pteromys volans orii (subspecies of the Siberian flying squirrel, endemic to Hokkaido)
sugar glider (species of flying phalanger, Petaurus breviceps)
Leadbeater's possum (Gymnobelideus leadbeateri)
flying squirrel