Help with gallon mollie

[Willcfm]

Over the progressing month, I've noticed an increase in growth in my balloon Mollie.
At first I thought nothing of it. Google searches brought up no results, and he always acted just fine.
He still does.
He swims and eats like always, without any issue.

But I noticed that the growths have grown alot worse, and I'm worried this is a heal concern.

Any idea what it is?

 

[SaraB]

Does it look fuzzy? Could be a fungal infection.