Jimson

 is one of the inhabitants of Point Lookout and a member of the Point Lookout Tribals in the year 2277

Daily schedule
He is the gatekeeper for the tribals at he Ark & Dove Cathedral and stands there at the gate the whole time.

Effects of player actions
You have to talk to Jimson to get in to the church for the Walking with Spirits quest, and tells you to go to mother punga plant and pick it's seeds to join the Tribals.

Appearances
appears only in the Fallout 3 add-on Point Lookout.