Can anyone id this mushroom ?

[Paveman]

I've got a couple like these growing on live rock and one is quite big. Anyone know a name and how big they get ?

 

[ccCapt]

Looks like an elephant ear mushroom. They can grow to 10" in diameter.
Elephant Ear Mushroom

 

[Paveman]

Thanks for that but I don't think so. Maybe my picture isn't great but it has multiple mouths (star like) with small fat tentacles around the perimeter.

 

[ccCapt]

Did you check the link I posted?
"The Rhodactis mussoides Elephant Ear Mushroom is a member of the order Corallimorpharia (Stephenson, 1937). It is usually brown or green, with a large wavy surface, a leathery texture, and multiple mouths."

 

[Rutrag]

I have some "green hairy mushrooms" that look quite similar. My largest is probably 2" in diameter. However, I don't think mine have multiple mouths.

 

[Bige]

+ 1 on elephant ear. The stars are just like the elephant ears and they get really big.

 

[Fishguy2727]

It is a Rhodactis, but I don't think it is an elephant ear. Elephant ears have a bare area along the edge of their disk with no tentacles. The mushrooms in question do not have this. There are many Rhodactis with large tentacles that can grow very large.