A ti-khana venomwing pterosaur is a diminutive but pugnacious reptile used by yuan-ti as a pet or scout.

Creatures of the Yuan-ti. Over millennia of experimentation, the yuan-ti have transformed various scaly reptilian animals into monstrosities that share some of their traits. Called ti-khana, these prized pets are carefully trained to serve their ophidian masters. All ti-khana are resistant to magic like yuan-ti and possess the innate ability to detect magic. The majority of ti-khana also have venomous fangs, the ability to transform into a poisonous snake, and some kind of supernatural or magical attack.

Ti-khana require the dark magic and alchemy of the yuan-ti to breed and develop their powers. Ti-khana can survive in the wild, but it is unlikely they can reproduce properly without the yuan-ti's arcane treatments. It is possible some types of ti-khana can mate with their unaltered relatives or lay viable eggs with their own kind. However, feral offspring can not develop ti-khana abilities without yuan-ti intervention so, at best, would grow into beasts resembling the ti-khana's mundane ancestors.

Breeding and training ti-khana is usually performed by specialist yuan-ti spellcasters, but an edifice can be enchanted to perform this task for one or more strains of ti-khana. This allows ancient yuan-ti sites to have a population of ti-khana "guarddogs" even if no yuan-ti has visited them for millennia.

VARIANT: VENOMWING FAMILIAR
Some venomwing ti-khana pterosaurs can serve spellcasters as familiars. Venomwing familiars are normally exclusive to the yuan-ti and their allies, but in rare cases other spellcasters may possess them. A venomwing familiar is typically hatched from its egg by its master and takes after them in alignment, so will not be evil if raised by a good spellcaster. In addition, a venomwing pterosaur must be fed unusual foods such as rare meats and alchemical ingredients to remain happy and healthy. Venomwing pterosaur familiars are always chaotic and temperamental, and constantly demand titbits and attention as payment for their service. Such venomwings have the following trait.

Familiar. The venomwing can enter into a contract to serve another creature as a familiar, forming a telepathic bond with its willing master. While the two are bonded, the master can sense what the venomwing senses as long as they are within 1 mile of each other. While the venomwing is within 10 feet of its master, the master shares the venomwing's Magic Resistance trait. At any time and for any reason, the venomwing can end its service as a familiar, ending the telepathic bond.​

(Based on a monster from the Fiend Folio (2003).)