What is this!?

[ianw163]

What is this and how to get rid of it

 

[Hats_]

Bristle worm, pretty good cleaners but dont touch them you'll regret that

 

[ianw163]

Will they grow very big?

Bristle worm, pretty good cleaners but dont touch them you'll regret that

 

[twentyleagues]

Will they grow very big?

They can. Biggest one ive seen in the past was about 4" when all scrunched up. I used to hunt them down and remove them. Then I realized they are a good thing, good cuc just not great to look at.