It doesn’t attack only when you have treausre. It’s random and in deep waters.
just travel the seas in deep waters away from the other islands
already answered that
you get treasure for each tentacle you destroy. It’s like a cup or something I can’t really remember. Once the Kraken disappears the treasure goes away.
Do you play on PC or XO? We got an achievement for killing it in a crew of 2. The Kraken is a damn beast so have one person dedicated to the cannons, one dedicated to repairing and the other dedicated to getting the tentacle out of attaching itself to the ship. They also suck up anyone on the ship so carry a shotgun on you so you can shoot yourself off or someone on a cannon can shoot the tentacle.