Unused Status Pictures[]
There are several status profile pictures for Kou that cannot be seen during normal gameplay. Two of the status ailments, Bell and Blind, do not exist in the game at all. The other two, Paralysis and Sleep, do exist, but since you cannot enter your menu screen while Kou is under their influence, you cannot see the pictures for them without using a Gameshark or other such hacking device.
Unused Monster Book Descriptions[]
Highlighted area is unused Monster Book descriptions, as viewed in Notepad.
The Azure Dreams GBC ROM contains several unused Monster Book descriptions for the characters Wumpi, Selfi, Kou, Ghosh, and Beldo. They are:
Wumpi = Selfi's pet; somehow different from other Wumps.
Selfi = It's Thelfi!
Kou = The guy you're playing!!
Ghosh = Ghosh - he does mess with you, but he may be OK.
Beldo = Beldo's a mystery, and not the kind you can trust.
This heavily suggests that it was originally planned for every character you meet in the Tower, including yourself, to get an entry in the record book. This idea must have been scrapped before the characters Skale, Attley, and Marzin were added to the game as they don't have entries.
In addition to having a Monster Book entry, it is also possible to hack Wumpi, Selfi's pet wump, into your party but she has the same sprites as a normal wump.