Hot water tank plug never seen one like this

8 point socket or square socket should be used on a square plug.

yeah, before I tried twisting that thing Id drill it out and at least wack the sides inwards a few thousands might be the difference of having or not having threads when you unscrew it.

Drill out the center with as large a bit as you dare, then a punch or chisel out the sides with the threads, should fold down onto itself.

My aluminium tank had galvanized plug as well, but with teflon tape it come off easy.
Some of those squares are in 3/8 or 1/2" size, meaning ratchet extensions might fit over and than having better grip on other end you can use good crescent wrench.

You need an 8 point socket.

I tried everything 12point sockets slip I haven't tried the heat I'll do that next

Someone put in the wrong plug..

Aluminum and steel, not the best of friends add water and you get electrolysis.

A brass plug would have been a better choice.

Since it has a square head, you can use a socket, but the trick is only one of the socket styles will fit.. You can try a 6 point or 12 point, I can't remember which one will work, but one of them will fit.

Then you can use an ratchet with an extension that is long enough to get the ratchet outside the tank.

You will need to take it slowly when removing the plug, there will most likely be a lot of rust in the plug threads inside the tank.

Turn the plug less than a 1/4 turn out, then reverse to tighten the plug then reverse to remove and take slightly past the 1/4 turn point. By reversing you allow any build up inside to clean off the plug threads which were exposed to the water.

Don't force it, if it tightens up reverse and the direction , you may need to repeat this a few times.

If you force the plug out you risk damaging the softer threads in the aluminum tank..

Once out, go buy a proper plastic nylon plug, they are dirt cheap at about $2 for a package of 2.

The Channel locks may be the problem, try a small pipe wrench. I don't think channel locks are very efficient at transmitting torque. You may also want to soak the plug threads with some sort of thread loosening spray, pipe blaster or some such.

More than likely that t has bonded together you will probably destroy the threads .might try heating the/area around the plug up and hitting the plug with cold