Here is a picture of my oscar that got attacked by my convicts (which i no longer have).
Do you think its tail will grow back?
Sorry about the picture quality

hard to say, from the pics.
They will grow back if the root of the fin is still there.
Mine had a bitten fin some weeks ago, and half the spine of the fin has grown back allready.
The middle of the fin looks bad, and I can't make any promises, but pristine waterquality and a varied diet should help your fish recover.

just don't keep him with the convicts any longer and he'll be just a new in a few weeks (assuming you have good water conditions). if you want you can speed up the process using melafix.

if the nipper is no longer around and water in tip top condition, it will
recover soon....

Thansk For replys .
Ido hope it does grow back. I only have the oscars in the tank now and they seam to get on fine.but very fussy eaters. they only seam to like prawns

Thats a lot of fin missing there. keep an eye for rot or fungus. hope it all grows back. some will and most likely all. best of luck with it. keep us posted as to how it gets on.

rot and fungus . Whats it look like?

Fuzzy white patches is what fungus and rot look like. Just like everyone else has said, keep your water conditions pristine and he should be fine. I use a bit of Stress Coat when things like that happen (nipped fins, owies from fighting, etc). There are other products that do a similar job out there as well. Good luck!

the fins should grow back soon but if it got flesh there could be scarring, though it doesnt look too bad, oscars can take a lot