Steven Universe

Thousands of years ago, beings calling themselves "The Crystal Gems" appeared on Earth. They kept to themselves, only coming out to fight extraterrestrial and paranormal threats, such as the Mollusc invasions of 1898 and 1939, as well as the 2012 cataclysm.

However, their leader, Rose Quartz, fell in love with a struggling rock star, Greg Universe, formerly DeMayo,  Rose had a child with Greg, although in order for the child to exist, Quartz had to give up her physical form. Greg named the child Steven, and raised him with the help of the Gems.

At some point, Steven and the Gems were visited by an imp from the fifth dimension, which would later be known as the Q Continuum  calling itself Uncle Grandpa. Afterwards, their memory of the event was erased completely.