The zakdir was a type of wool-bearing animal lifeform native to the planet Capella IV.
The zakdir were useful to the Capellan civilization, who used the animals as a source of wool for textiles. In the 23rd century, the wool was valued as an export of Capella IV, having been traded to visitors from Earth. (TOS - Star Trek 3 novelization: Friday's Child)
A friendly reminder regarding spoilers! As always, the expanded Trek universe is in a period of major upheaval with the continuations of Strange New Worlds and Prodigy, the advent of new eras in gaming with the Star Trek Adventures RPG and Star Trek Online, as well as other eventful releases such as Section 31, the ongoing IDW Star Trek comic and spin-off Star Trek: Defiant. Therefore, please be courteous to other users who may not be aware of current developments by using the {{spoiler}}, {{spoilers}} OR {{majorspoiler}} tags when adding new information from sources less than six months old (even if it is minor info). Also, please do not include details in the summary bar when editing pages and do not anticipate making additions relating to sources not yet in release. THANK YOU
READ MORE