Thala-sirens are pinniped like creatures that are native to the coastal regions of Ahch-To.
They are docile seal like animals that are known for sunbathing in the rocky cliffs of Ahch-To. They were described of having a long snout similar to Eopies from Tatooine, four flippers and grayish skins with pink underbellies (sometimes covered with barnacles). They have no fear towards to the Lanais which makes him harmless. The females were famously known for producing nutritious green milk as one was shown harvested by Luke Skywalker during his time in their home planet.