Resembling 15 foot long cobras, the Kaa have bunches of tentacles for arms and a vision band across their head, as opposed to 'eyes'. They see in the infrared and ultraviolet spectrum.
Their venom is not poisonous so much as extremely caustic and used in some industrial processes due to its unique properties.
They are an outlier race, producing some mercenaries. Also, because they are an arboreal species who can flatten their ribs and glide, they have excellent 3d spatial awareness and make excellent pilots.