Ape. The Ape was created by Yevgeni Zamyatin (D-503) and appeared in the play Afrikanskii Gost’ (1929-1930). The Ape is an African ape who is slowly converted to Soviet Communism through careful indoctrination.
Pao-Pao. Pao-Pao was created by Ilya Selvinsky (Umka) and appeared in the play Pao-Pao (1933). A German scientist transplants the upper layer of a human brain into the head of an orangutan. The result is Pao-Pao, who the scientist teaches to become a proper communist. He succeeds, and Pao-Pao tries to help his primate brethren in the Moscow Zoo, but he is rejected by a gorilla, and when a Soviet scientist tries to rescue Pao-Pao the scientist is killed. The play ends with Pao-Pao holding up the body of the Soviet scientist, turning to the audience, and saying, “Now do you understand the meaning of life?”
In the late 1920s the Soviet kransyi Pinkertonitscha movement–the “Red Pinkertonism” movement which made use of the classic tropes of adventure and dime novel detective fiction, but slaved them to the theme of international class struggle and the triumph of Revolution–was running out of steam and was being replaced by a requirement (which became a formal government decree in 1932) that Soviet literature and film must be explicitly collectivist and Communist, and literature bearing foreign influence, such as genre fiction, was fundamentally suspect. So in the late 1920s you could still have explicitly genre work like Afrikanskii Gost’, but by 1932 something like Pao-Pao is politically suspect and has to cover its genre origins by frontloading the ideologically acceptable material.