According to Arin Hanson from Game Grumps: Desert Jellies are what the navy calls it when you jerk off in the shower, since you rarely get any alone time except for when you're in the shower. If you jerk it too much however, it will clog the drain, and your "desert jellies" will float back up to the surface.
This is from their BOTW playthrough btw.
"The shower drain got clogged again," Person #1 said.
"What? How?" Person #2 asked,
"Desert Jellies," Person #1 simply replied.
B. Johnson: "Are you saying they're abdicating their duty to scrutinize me?"
"Are you saying that they haven't the guts to put the questions to me?"
"Great supine protoplasmic invertebrate jellies!"