Weird growth on trochus snail

[ohioboy12]

Hi all. I’ve noticed this design on my trochus snail since I’ve got him about 4 months ago. I’ve noticed this weird snake looking design on its shell has grown. Can someone please help me identify what’s going on? Thanks in advance

 

[BaliReefBox]

looks like a tube worm/snail....

 

[ISpeakForTheSeas]

Looks like your snail has some kind of tube worm living on it.