Illness/Sickness: Sick Axoltol: gill fungus, growth, or something?

please help! I'm not sure whats the matter with my little albino friend! He seems to have some kind of strange growth on his gills...It is covering one of his top gills, and spreading to the other side. I noticed a small bump yesterday, but now it's grown ten fold!

I'm not sure what to do!

He was in the same tank with 2 other axolotls, can this spread to my other babies?
Is it fungus? Is it an infection? How do I cure him?

as of right now, he has been seperated from his brothers and is in his own container.

You got yourself some fungus it appears. Salt baths are going to be your best option, and can be done as seen on this site...
Axolotls - Health & Diseases

Check the Bacterial and Fungal Problems Section.

I would recommend salt baths (once or twice a day) using 2-3 teaspoons of aquarium salt per liter of water. Leave your axie in the mixture for 10-15 minutes, and then return him/her to a salt-free enviroment. If your axie seems to really dislike the experience, you can dilute the mixture a bit.

You might even consider fridging him/her, but I will let an expert chime-in on whether or not that would be a good option.

I have treated my axies in this manner when they got a bit of fungus on their gills, and it cleared up very quickly. Sometimes cooling the tank down can help keep fungus under control as well as adding Holtfreter's solution to the water. The salts in Holtfrter's solution restore hardness after water treatment and help maintain the axie's health by discouraging parasites and fungus.

I've got some standard aquarium salt and I put a bit of that in when I was cyling with the axie in the tank and I had some nitrites. Since then, no more salts added.

I've seen the chemicals in Holtrefeters solution - can you buy the solution from a shop or do you need to DIY?

You can buy Holtfreter's salts from the Ambystoma Genetic Stock Center at the University of Kentucky.

Here is the link to order supplies:

Ambystoma Genetic Stock Center

I've been salt-bathing him since yesterday, and it seems like he is improving!

At first, he really didn't seem to enjoy the salt bath, I think this was mostly due to the pain caused by his fungi-infested gill. He calmed after a bit and is on the road to recovery!

many thanks for everyone who left advice for me!