Although usually there is no ill-meaning behind the term, it is often used to poke fun at younger surfers. It can sometimes be used as a derogatory term when younger surfers are annoying, bad or otherwise difficult.
It is frequently abbreviated to grom.
powers is a grommet
A possible etymology for the word may be from the Portuguese term 'grumete', meaning the lowest ranking person on board a naval ship - this word would have been used widely in South Africa in the period when surfing was becoming popular.
The animal is usually described as "The Grommet" although they appear in large bunches when required. Such groups are referred to as flocks due to their tendency to find themselves brought into existence only to be airborne. As such their species has evolved to be of a highly durable, impact resistance creature.
They also exhibit tendencies to wear crash helmets, Viking helmets, capes, and Santa suits.
Origin stems from misconception of the word "Grommet" and "Gerbil" during a student's physics quiz. Student did not find it amusing that a gerbil would be dropped from a tall and aloud to impact the ground, although concern for small animals was lost after be told that a "Grommet" was a small metal washer type object and not an animal.