What are these on my rock?

[Fish-guy]

These things started to grow out this rock after a few weeks. Anyone know what this is?

 

[Fish-guy]

Added a bigger picture. Maybe it helps

 

[ClamSnorkler]

Those r aptasia, they r a common pest anemone. They sting fish, spread rapidly even in poor conditions, & compete w/ corals for food & nutrients. Often they hitchhike in on live rock or new corals. Peppermint shrimp love to eat them & should b a part of any clean-up crew anyway. If the shrimp aren't handling the aptasia then u can use Aptasia-X. I kno from experience that it works great, ur LFS should carry it & b able to show u how to use it. It's really easy. Peppermint shrimp r cheap, easy & fun to watch tho

 

[Leighton79]

I'm not 100% sure about that. I'm only viewing on an iPhone but they look a bit like zoo polyps to me.

 

[SHARPiE]

These aren't aptasia, they look like polyps.

 

[joy13]

Just poke it if it balls up a polyp of some type if it disappears into the rock some type of anemone. My thought is polyp.

I know I am not the only one around that pokes things in their tanks.