things i cant be bothered to try but might work:

deltarune/undertale characters (Gaster, sans, toriel, ect)

the new nymphs and satyrs (ly'lac, swiss, whoevers next)

nicknames and "real" names for guardians made by fans (Roxanne, broderik, solluxander, karkles, ect)

some obvious ones that werent there (maplehoof, scratch doctor, bec noir)

the important numbers (413, 612, 1111, 1025)

the memes (sharpie bath, togor dremur, pantskat)

the organisations (fraf, hicu, what pumpkin, furthest ring studios)