I decided to call my Alien species a Nuwi

A male Nuwi has an incredibly long tail that has a hidden poisonous needle-like bone within the tip. It's retractable and is mostly used in threat displays or hunting. Females have them too but their poison is weaker and serves more as a deterrent than a weapon.

Males are around the same size as a female but just like humans, they can range from female-like to very masculine.