Jackie is a Hyena Spirit that was released as part of the Spiritfarer: Farewell Edition along with Daria the Bat. In order to recruit him on your boat, you'll need to finish Daria's Storyline first. 

Jackie is a Hyena Spirit that was released as part of the Spiritfarer: Farewell Edition, along with Daria the Bat. In order to recruit him on your boat, you'll need to begin the story at 

Because they are hidden behind the mist, Jackie and Daria are both late-game Spirits you can bring onto the boat.

Jackie is an orderly at the Overbrook Hospital and complains for the most part about the poor condition it's in and the work they have him do. You'll be asked to complete multiple tasks for him ranging from wrangling patients to feeding them.

Eventually, he will leave his post at the lighthouse, allowing you to enter and climb up. At the top, you'll find Daria. While this will draw his ire, you'll need to help and interact with Daria to proceed.

Keep helping Daria and Jackie until the quest, "The Incident", appears. Jackie will be furious at you and will quit his job and leave.

you will not see Jackie again until you've brought Daria to the Everdoor.

Daria's story will involve clearing up Overbrook, using the Vending Machine to fix it up, and completing her Mind Palace Events.

Here's the list of all quests you'll need to finish!

After which, you will be contacted to bring Daria with you to the Everdoor in the quest: Impression, Sunrise.

If you do not bring Daria to the Everdoor, she will remain silent in your room and cannot be interacted with.

A few days after bringing Daria to the Everdoor, a resident on your boat will make a comment on hearing noises at night, prompting the quest: Perimeter Sweep.

You'll find Jackie hiding out in Gwen's home! Speak to him and he'll join your boat!

How to Recruit Jackie on Your Boat