Hitching on my chalice plug. Good or bad?

[joekidwell]

I'm thinking bad.

 

[joekidwell]

It has a friend with two horns on its head

 

[Anemone_Fanatic]

Stomatella snail. One of the best algae eaters for our tanks and completely reef safe. The only bad part about them is that you rarely find them for sale. Good guy to have.

 

[Soren]

The first creature definitely seems to be a stomatella snail. I've only heard good things about them as Clean-Up Crew and would love to get some as hitchhikers and would even pay to get some when I'm ready for them.

The second pictured creature seems to be some type of sea slug or possibly a nudibranch, but I don't know what type.