I have never seen a fish like this and the authorities here are also confused about what this is... Can anyone here identify this weird fish?

It's a Tigerfish. Where was it found?

Looks like my mother in law before she has a coffee in the morning .

Not a Tigerfish, they don't have teeth on their tongue. Looks more like a buck salmon.

Looks to me like an eel. The teeth are too small and too numerous to be a tigerfish. At first I thought it may be something like a mackerel, but after a close up the teeth are conical not bladed, so it's not a pelagic, more like demersal. Ambush species that grabs it's prey and holds on to it. The small pectoral fins also point towards eel. A look at the tail might confirm it.

This is a spent Chinook, you can clearly see the teeth on it's tongue. I've caught buck Rainbows similar. Be interesting to find out where it came from.

Yep, you'll only make the mistake of going the thumb grip on a big buck trout once.