Need Help To Identify Wound/Disease on Homeless Cat [URGENT]

Since August this year there is a cat that has been coming around to our house.

It seemed like a nice cat so I usually gave it some food when it visited (couple of times each month).

I was also assuming that it was homeless as it didn't have a collar and always seemed really hungry.  It was either homeless or it had a careless owner.

The only sign was a green "stamp" in the ear but I couldn't really read what it said.

It came over today and I went out to greet him/her when I noticed that it had several (I noticed 2) wounds and something that looked like worms on the side.

Now this isn't my cat but it feels really, really bad to just let a cat rot away so I threw a large chunk of food out and it ate all of it.  At the same time I tried contacting a vet but most of them are closed due to the weekend but there was one open and they were on a break so I'll have to try again later.

I was able to snap one picture through the glass door:


It was dark on that side of the cat so it's not very clear.

I need your help to urgently identify the problem and see what kind of issue this is.

If it's a serious injury and the cat is in need of urgent help then I will contact a vet and see if they can drive here, take it in and take care of it.

I am also sorry for the strange formulations, I am doing my best to type as fast as possible as the vet is closing for the day in about 50 minutes.

If one vet is open, drop the cat off.

I called a vet that was open but they can't pick it up.

The person I spoke to gave me a number to something called the 'animal ambulance' which will come pick it up.

But as soon as I found out about them the cat left (about 20-30 minutes ago) and I have no idea where it currently is.

The options are:

1) Hope that it recovers on its own (I gave it a large amount of food which hopefully helped).

2) Wait for it to come back so I can call the animal ambulance.

Forgot to ask if you had any idea what kind of wound/disease this is?

Maybe you could leave some food out for the kitty, then grab him to take to the vet. I would try to help the poor kitty, if you can. No idea what the wound could be. Possibly got in a fight and it has become infected/infested?

Are you able to pick the kitty up and put in carrier?  I know of no vet that would come and pick a kitty up so you will have to do it.

There are organizations that will loan you a Have a Heart trap.  Ask your vet if they can refer you to someone who owns one.  My vet refers people to me for my trap.

There is no way we can tell what the problem is with the cat.  It is not visible.  Could be a fight.  The worms could be maggots.  Don't have a clue.

You are wonderful to care for this kitty.  I hope you can catch him.  There are emergency clinics in many areas.  Check if there is one near you.  The poor thing is in pain and needs attention.

My thoughts and prayers are with you and hope you can catch him.

Alright, I'm back.

Of course I fed the cat but I don't think it was such a smart move as it left right after I fed him/her.

I should've stalled it until the vets arrived.

Anyway, something really strange happened as the cat returned yesterday night but this time it was completely normal and had absolutely no sign of any wounds.

This has made me suspect that there are actually two cats with the same patterns and colors, but right now I'm not really sure.

If the wounded cat returns I'll without a doubt call the animal ambulance right away at the same time as I try to keep him there until they arrive.

Thanks for the support, it's truly appreciated!