What was the name of King Friday XIII's northern mockingbird?

King Friday XIII’s northern mockingbird was named Mimus polyglottos. That is the scientific name of the northern mockingbird, one of the king’s two pet wooden birds in the Neighborhood of Make-Believe.

The bird was represented as a wooden bird on a stick rather than a live animal. King Friday referred to his pets by their scientific names, giving the royal character another opportunity to use the elaborate vocabulary and formal speech that defined him.

The other royal bird was Troglodytes aedon, the scientific name of the house wren. This is the key distinction behind the question: both names belong to King Friday’s bird pets, but only Mimus polyglottos identifies the northern mockingbird.

In real-world biology, the northern mockingbird is a North American songbird famous for imitating other birds and environmental sounds. The species name combines Mimus, meaning “mimic,” with polyglottos, referring to its many-voiced or multilingual vocal ability. The show’s choice of name therefore fits the bird particularly well.