u/breedingbreads

My cat is is a larger male, and felt this bump on his neck almost over night. He cuddles with me nightly so I know it wasn't this size last night or even noticed at all. Is this something I can just monitor or should I take him to a vet? First time owning pets by myself long term and just wondering the severity or any tips on how to gage these matters.

UPDATE: Herman is fine his sister kitty probably just got him good one time. No ring worm. The vet said ringworm is quite uncommon to be diagnosed without some sort of immune system suppression. WHAT A MORNING LOL Thank you for the love and concern of my fur baby.