In addition to the many anthropomorphic characters depicted in Mao Mao: Heroes of Pure Heart, there are also a number of non-anthropomorphic animals shown in the series, though many of them are often relegated to incredibly minor roles.
Known Non-Anthropomorphic Animals
Yellow-Hearted Blue Birds
A number of small, blue birds with yellow heart-shaped patterns on their chests can be seen in various episodes. A more rotund specimen can also be seen in "Mao Mao's Bike Adventure".
A number of cockroach-like insects can be seen in various episodes. They resemble real-life cockroaches, except their antennae curve inward to form a heart-like shape. Both Ratarang and Adorabat have eaten these creatures, as seen in "All by Mao Self" and "Trading Day", respectively.
A number of scorpions can be seen in "All by Mao Self", wherein Mao Mao uses them to purposely hinder his hands to physically challenge himself. Later in the episode, Adorabat dumps a bucket of scorpions onto two of the Sky Pirates.
A number of ducks can be briefly seen in "Meet Tanya Keys".
A dolphin can be briefly seen in "Meet Tanya Keys", wherein it is regurgitated by Mao Mao while he is being dragged along the ocean's surface by Tanya's Aerotruck.