What is this thing?

[PrimoReefer]

I've seen it a few times scooting across the sand and glass but I have no clue what it is or if its good or bad

 

[PrimoReefer]

BTW.....that white patch on the glass was left by this creature. Not sure if its eggs or what

 

[sellersmd]

Tagging along. I'm pretty savvy with my inverts but no clue on this one. Only REMOTELY close guess would be some kind of flatworm?

 

[rssjsb]

Looks like a sea hare

 

[Betta132]

Sea hare, I'd say. Go and look them up to find out how to care for it.

 

[Calappidae]

Flatworm?

He seems too flexible in the last pic to be a sea hare.

 

[fishy.22]

Looks like: Dolabrifera dolabrifera, a flat sea hare that grows to about 4cm. Harmless vegetarian.
Look here:
http://seaslugs.free.fr/nudibranche/a_dola_dolabrifera.htm
D. dolabrifera feeds on turfing green algae.
Give it some greens and call it a cool hitchhiker.
Great pics.

 

[faithenfire]

i think he is too big to a flatworm, i would say a flat sea hare is right.
sea hares will help keep algae down. and when/if you don't have any try nori or veggie food if you would like him not to starve

 

[rssjsb]

i think he is too big to a flatworm, i would say a flat sea hare is right.
sea hares will help keep algae down. and when/if you don't have any try nori or veggie food if you would like him not to starve

polyclad flatworms can get very big. However, they don't have "ears."

 

[PrimoReefer]

BTW...since I spotted this one I spotted a few more but they're a little smaller. If they're on the glass it just looks like a snail.