Two Id's

[Azazael13]

I was visiting my dad recently and he had two things in his tank we couldn't ID, so I thought I would seek outside help

I am wondering if this is a sponge of some sort, he has a few of them all over the rocks.

We thought this might be aptasia at first, but if it is, it is the biggest aptasia and bravest I have ever seen. The coloring doesn't quite match either.

 

[landlord]

Tunicate and a curly-cue anenome.

FWIW --landlord (I have been know to sometimes guess wrong)

 

[Diatome]

The first one is a tunicate (sea squirt). Harmless filter feeder.

The second is a Curly Q Anemone. Some call them pests and others buy them. Go figure.