Stylised rendition of two creatures native to ia'Maura, where "Thunder Daughter" was set. I was going to a sort of stylised Aztec/Maya look, as that's part of the basis I used for the Qii society (the natives) that "adopt" Mirii (the heroine).
The green one on the left is a "zochi'coatl", aka flower-serpents or "lotus born". They look lizard-like but they're actually mammals, with scaly armour like a pangolin. The crest slowly unfurls over the course of the first part of the year, like a fern, then is shed in autumn. Because of their appearance, the Qii consider them to be spiritually connected to plants. They're hard to spot and even harder to catch, but easily tamed if caught as a griz and hand-reared.
On the right is a nut-foot (I still need to think of a Qii name for them); their name refers to their little hoofs. They're a semi-intelligent semi-domestic species - capable of a small degree of abstract thought, but not very clever. The Qii use them for a variety of purposes - guarding, and hunting, mostly, and also eating, although great care has to be taken on the latter, because their skin is highly poisonous.