Grim Reaper

The Grim Reaper is a Level 190 Sea Creature that can be fished up during the Spooky Festival when the player is  (26) or higher.

Its special ability is like the Scarecrow's, dealing damage from a range, using projectiles similar to the Frozen Scythe's ability.

You could get two Soul Fragments due to the “Finder” perk from the Hound Pet, but this has been removed.