Arkanadons

Arkanadons are 5 block tall monsters found deep dark lakes and deep ocean caves. the have 8 squid tentacles, a humanoid torso and the head of a hammer head shark. they are intelligent semi-neutral mobs that once ruled the deep dark and enslaved all who lived there (explaining the hammer head shark statues in deep dark cities) they were mostly destroyed after a slave uprising. they attack with magic weapons powered with gems. this includes electric tridents, very long ranged harpoons, and lobbed glass bottles filled with acid. arkanadons are evil but not unreasonable. they may trade safe passage for gems if encountered (the number of gems can range from 1 to 50. it's always random) if denied they attack. gems include diamonds, emeralds, amethyst, and maybe new ones like topaz and sapphires. with enough gems they might become friendly to those who have given them large amounts of gems. they appear suddenly out of a lake players are trying to travel through  to demand tribute. if denied, they attack other wise they stay to demand more random tribute. they may guard huge shipwrecks the dragged down. they always wrap their tentacles around a boat to stop it from leaving while they demand tribute.