Complex sentence: Terror Jr is an American pop duo formed in 2016 founded by former The Cataracs band member David "Campa" Benjamin Singer-Vine, Lisa Vitale, and Felix Snow, who left the group in late 2017.
Split into simpler sentences: Terror Jr is an American pop duo formed in 2016. Originally consisting of Felix Snow, former The Cataracs band member David "Campa" Benjamin Singer-Vine, and Lisa Vitale, Snow left the group in late 2017.