According to a site I use - Garland Tools Database (very handy site) - they drop off 3 monsters in lvl 50 dungeons. Baravoid waste in The Wanderer's Palace lvl 50, the congealed Bloods in Haukke Manor lvl 50 and Corrupted Pudings in Pharos Sirius lvl 50. If you have a retainer that is a disciple of war or magic, there is a retainer venture you can send them on as well.

This site I use - https://www.garlandtools.org/