A species of anthropomorphic snakes from Trials in Tainted Space. The Slyverens have made heavy use of biological modifications to craft the appearance and abilities they possess now. Bipedal legs, mammalian-style breasts, long tails to counterbalance the biggest chests the galaxy has to offer, bright, flashy scale colors, telepathic capabilities and a refined venom.
Due to the modifications, the venom intentionally lost its toxic capabilities, effects were made more potent, suppressing voluntary muscle activity and subtly altering brain chemistry to reduce inhibition. Elasticity-enhancing chemicals allow even the most endowed males to fit their cocks down a Slyveren's throat, also a necessity considering another add-on is the expansion of male genitalia.
While the modifications of their bodies mostly served to appeal to the intergalactic masses, the changes to their venom were made to easier feed off the sexual drives of other species’ males (Yes, they changed their genome to easier get thoat-fucked and drink cum). More criminal elements among the Slyverens use the addictive properties of the venom along with their psychic abilities to turn males into big-dicked, willing slaves.
The Slyverens are all female in appearance, but are biological a kind of hermaphrodite. They produce eggs, which are transferred to a partner basically via tribadism and then fertilized in the recipient's womb by internal ovary/gonad glands.

For more information: https://wiki.smutosaur.us/TiTS/Slyveren