How about a one page Beatles-themed underwater D&D adventure featuring strays from a vast Army of the Drowned Dead? I think they're mostly here for the hip music, or some shadow of a feeling that music once gave them. Maybe they just need a little hand-holding.
Full-size link
https://www.dropbox.com/s/ucak3rlkurjrqrv/TheBEATlesMorts-DnDOneShot_ChrisHoward_20201012-14.jpg?dl=0