Pixies

Pixies were tiny Fair-Folk created by the Life Wardens to serve as companions and handlers for Arbs. Because Arbs possessed Elven-derived semi-sapience, the Wardens required another Fair-Folk capable of understanding their deep thrumming speech, but small and mobile enough to live alongside them without burden. Elves were Biowoven with insects and stabilized at butterflies, eventually producing fully sapient, winged people generally six to twelve inches tall, with different butterfly-derived phenotypes accounting for much of their variation in size, wings, and appearance.
A small Pixie family typically lived upon a single Arb, making homes among its branches and hollows. They kept their Arb socially engaged, encouraged migrations, interpreted the rapidly changing world around it, and prevented excessive dormancy; Arbs left asleep for too long gradually became increasingly tree-like and difficult to awaken. In return, the Arb provided its Pixies with transportation, protection, and a living home. Their relationship became one of friendship rather than simple control.
This partnership finally made Arbs dependable forest sentinels, allowing Pixies to distinguish allies from enemies and communicate dangers their plantlike companions might otherwise misunderstand. Arbs without Pixies tended to become increasingly wild and dormant, while Pixies who abandoned life with an Arb gained a reputation as unusually adventurous, rebellious, and mischievous. Together, Pixies, Arbs, and Wood Elves formed a distinctive interdependent woodland society within Naja.