Mantis

Mantis is from an empathetic insectoid race and one of the main characters in Guardians of the Galaxy Vol. 2.

Early Life
Mantis was born from an unnamed home world and descended from an empathic race of insectoids that would eventually reach to a humanoid state. She was found at her larvae estate by Ego, who took her from the planet and raised her since she was a child. Growing up on Ego's planet, Mantis was raised and kept from the outside world, causing her to develop a naïve personality.

Growing up, however, Mantis was never loved by Ego and often helped him fall asleep using her empathic powers. She was well aware of Ego's Expansion plan, but never blabbed to anyone about it.

Powers

 * Empathic abilities: Through the use of her antennae, whenever Mantis touches someone, Mantis can feel their emotions. For example, when she touched Peter, she felt his romantical feelings towards Gamora. When she touched Drax the first time, Mantis could feel a humor she never felt before. Mantis later used her powers on Drax, where she felt Drax's sadness of how Ronan the Accuser killed Hovat and Kamaria
 * Pathokinesis: She can make a sad person happy, and calm down a stubborn person
 * Sleep inducement: To an extent, Mantis has the ability to put someone to sleep. However, she only does this to help her master, Ego sleep. She performed it on Drax once, with his insistence. It is proven that Mantis is a very powerful entity and can put Ego to sleep on his planet surface rather than his human form.

Trivia

 * Mantis is probably older than Peter due to her knowing most of Peter's half-siblings and knowing of Ego's "expansion" plan.
 * In the TV series, Mantis is a villain and an enemy of the Guardians of the Galaxy, and is part of the Universal believers.
 * The name of Mantis' species is unknown.
 * She is the second guardian whose species was never disclosed, along with Drax the Destroyer (Rocket doesn't count because he is identified to being a raccoon (according to Peter Quill)