Mantis is an human/plant hybrid who was raised in Vietnam. When she met the Avengers, she fell in love with the Swordsman (Marvel), and she joined the team. She left Earth when Swordsman sacrificed himself to save the Avengers, but temporarily returned to marry his ghost. She then joined the Guardians of the Galaxy.
Marvel Cinematic Universe
Mantis is a young woman raised by Ego. and recruited as a member of the Guardians of the Galaxy.