The Fly Guy R Thieves are bosses that appear in Mario & Luigi: Dream Team. They are basically Fly Guy Rs with no changes whatesoever. They first steal the Driftwood Jellyfish Sheets from Mario and the rest but Mario manages to come up with a plan to steal them back. Angry, the Fly Guy R Thieves then fight Mario and Luigi.
In battle, the Fly Guy R Thieves basically attack like regular Fly Guy Rs mainly by bringing in Goomba Rs to attack then hovering over Mario and Luigi.
- Oddly, even though they are just Fly Guy Rs, they share the Boss theme song (Never Let Up!) for this game.