Vermetid Snail?

[SquattingSnail]

Are these vermetid snails?

 

[WVNed]

Those are sponges
Pineapple Sponges -

Very common good hitchhiker. These little guys are a type of sponge. They are most commonly found in overflows and in high flow areas of the sump. However, they can sometimes bee seen in shaded areas of your rockwork.

 

[Cantusaurus]

I'm not too familiar with Vermetid Snails, but to me I immediately thought it looks like a Pineapple Sponge.

 

[Cantusaurus]

Oh, well someone beat me to it But yeah they shouldn't be too bad of a hitchhiker. They should also take some silicates out of your water if you have any.