Help! I need help identify this critter(pod,bug on rock)

[ReefNewbies]

Help! I need help identify this critter(pod,bug on rock)

I have 20 gallon nano reef tank, and i'm pretty new to this hobby.

tank is 2 month old, 2 clownfish with some inverts.
0 Ammonia, 0 nitrite, 10~20 nitrate, 1.024, 400~450 calcium, 10dkh
had brown diatom recently on rocks but gone and green algae came.

Today, i found this little critter scavenging around live rock and looked like its eating green algae.

Can anyone identify this critter?

I have no way to get better quality of pic or video.

here is link of video





Thanks!

 

[saltyphish]

Looks like a pod to me. No worries.

 

[Downbeach]

http://reefkeeping.com/issues/2004-09/rs/index.php