It works on everything, even the Sea Dragon. Well not really because it will immediately swat your Seamoth out of existence but yeah.

If you use the cyclops on slow and silent running, then leviathans can pretty much only target you if they bump into you. It's very helpful for getting by them.

I only get attacked by ghosts when I attack them, if you stay as far as possible, they won't bother you too much

For reapers all you have to do is blast them with a Stasis Rifle and either use the Prawn suit claw/drill arm or your knife to kill them (or you can just run away once you hit them with the Stasis Rifle).

Also if your in your Seamoth you can use the perimeter defense to zap them. Or if your in the Prawn suit, use just hit them over and over again with your claw/drill arms

Also @VegetaFan756 they seamoth can't go that deep

@Silly Reefback Perfect!

They can only reach the lost river

Well then you don't need to worry about finding Sea Dragons and dying.

Yes

@Pekkachugirl11 I suppose you could always use the PRAWN grapple arm, and there is cave sulphur and nickel outside the ghost leviathan's territory in the green brine, so you can get the jump upgrade. When you get to that point, it becomes easy to simply ignore most leviathans. It might be hard to hit a charging ghost with a stasis rifle since it throws its head around so much.

@Raichu047 Thank you!