So for the last day or so my tiger Oscar has become extremely aggressive towards all my other fish, he locks lips with my other oscar every time they see each other and they spin and hit up all the sand. And he chases my other fish around like crazy, and they all hide. And he just swims around! and everyone else is hiding in fear!!
What should I do!
I dont want him to land up killing my other oscar!! Or my other fish!
please help.

You could try the time out NET!!!

Catch your Oscar in the net, And brace said net on the side of the tank.. So he is IN the water but can NOT get to the others... Prepare yourself as the last time I did this, my floor got SOAKED!!!

Leave him in there for an hour or so, and let him watch the others take over HIS territory!!!

This may work and it may not... But it is worth a try!

BTW... How big is your tank and what are the tank mates???

265, and i also have 3 fire mouths, 3 bala shark and 1 other oscar they never use to fight, but suddenly he snapped. I tried moving things around and everything but still he continues to fight

Try what I posted... You may have to do it a couple times... But if it works it is worth a shot...

You are in NO WAY over stocked... I think your Oscar is just being a shit.

How old is he?

Hes about 6 months old, and i will give your idea a try. Anything is worth a try at this point!

Hello Ripspring,
Is your tank 265 gallons or liters?

Gallons

ive had it for a long time, until recently i started to keep cichlids, before i had some native species in it.

sometimes oscar get more aggresive as they get older. You can only hope things get better.

One alternative is to separate your tank with a divider with the aggeesive oscar in one side. Leave it like that for a week or so and then put the aggressive oscar in the the oter side. If they get on then reomve the divide after 3 or 4 days. If they dont get on then consider rehoming

I think im going to have to rehome :/