Nothing to worry about. Looks like poop or remains from the frozen shrimp.
Well I hope it's not poop -- white poop is almost never a good sign in a fish tank. Can you net or siphon it out (which I would do in any case) for a closer inspection?
Looks like a worm, net it out and see.
Hard to say what it is. Net it out and see.

When I touched it it just smeared and the towel absorbed it.
Yes a PB. Just regular household garlic? What does it do?This is from a bass? Do you ever mix garlic in the food? Couldn't hurt.