Illness/Sickness: Lump/bump/growth on tail?

Hello! Looking for some advice regarding a weird lump on my axolotl.

Before anyone asks, water temp is high 60s (F) cooled with frozen bottles and parameters are normal. He's been living in the same aquarium since I got him, so I don't think the lump is related to his tank. The only other critters living in there are some tiny snails that hitchhiked on some plants from the pet store- but those have been breeding and living in there since before I got my axolotl.

He's about six months old and a couple months ago I noticed he had a tiny white pimple-looking thing on his tail. It's some weeks later now and the bump has grown considerably larger- it looks to be a little bigger than a pea, now.

I think maybe he thrashed around a little bit a while ago and injured that spot somehow and his body's just gone a little confused with trying to regenerate his injury?

Should I just leave it alone? It doesn't seem to bother him at all or hurt him, although his tail sits tilted to the side a bit when he's idle now. Whenever I poke at it with the chopstick or touch him he just treats it as if I were touching any other part of his tail. I've felt it and it's not hard or anything- it just feels kind of squishy like the rest of him. There are even veins and stuff I can see growing through it.

If it is a case of regeneration gone awry, I've read of other people's axolotls growing extra arms or gills and owners just kind of... snipping the extras off...? I really would rather not have to do this for obvious reasons.

I know people will probably just tell me, "take him to the vet", but I figured I'd try a nice, free alternative first. I live on Oahu in Hawaii and the only exotic vets I know of are crazy expensive.

Also, a little unrelated, but can anybody tell if this is a boylotl? It sure seems like he's got boy-bits, but I wanted to be sure because I was going to introduce him to a tank with another boy axolotl and I don't want to be an axolotl grandma.

Thanks all,
-Poodlay

Okay, this is REALLY just a guess, but it does look like a tumor. As for what you should do about it, I think you might need a vet for this one.

6 months old is too young to be certain, but I would guess he's a male. His finger tips havent gone dark yet though, so he isnt even sexually mature yet, so I would really wait. The big problem you are going to have getting him a friend at this point would be even if he was mature, finding another axolotl that is the same age\size who is ALSO mature would be highly unlikely which drastically increases the likely hood of you being a grandma. I would suggest waiting at least two months . I have had the same "problem" with mine in that I have had to wait before even beginning to look at getting him a friend.

Thanks for the reply.

Ugh, I guess I should start looking for a vet.

As to the tankmate issue, I already have another approximately 3y old boylotl in a 20gal long all by himself and thought he could use a friend. I've been waiting for this guy to grow out more so he won't become lunch.