The attack was sudden, and Captain Jack wasn't sure he could win against that beast. Many powerful ones roamed around the oceans, and sometimes an attack of such beast means death.
It was a good thing he met Arthur, who would help him deal with it for a favor. A favor? What could Captain Jack possibly do that Arthur couldn't? That's what he had in mind when he accepted such an offer.
"Let's go, Frostpeak. This is our first test together! Kill the beast!" yelled Arthur, to improve everyone's morale.
A tremendous splash of water, and a gigantic beast came out of the water. It had at least 20 tentacles and was half the size of Jack's ship. It was like a huge octopus with a scary face and teeth.
Arthur ordered the members of his crew to chant their spells and aim at the beast. He did not know how he would attack such a beast in melee combat. The only part he could think of attacking was the tentacles. So, that's what he did.