Portuguese sisters Júlia Reis (Drums) and Maria Reis (Guitar, Keyboard) have played music together since their teens with both contributing vocals. The sisters were born and raised in Lisbon and decided to perform as a duo after playing in various other bands. The band's name is a reference to the popular 90's toy known as "Sticky Hands", which in Portugal were called "Pega Monstros" and were often given as promotional items in children-oriented snack food packages.