Both the Mother release and the EarthBoundprototype contain unused graphics. The game's palette data doesn't seem to be stored in order, so if the graphics ever had palette values assigned to them there isn't any good way to match them up.
This pillow enemy graphic was probably originally planned as part of the opening sequence where the poltergeist attacks through objects in the house. This is really the only place in the storyline where a pillow as an enemy would make sense.
This little girl might be another doll that would have attacked the player in addition to the one that plays the melody. The text "Spooky!! The doll walks by itself!" can be seen at the beginning of the storyline script with the rest of the text from the event. The line that's there in the Japanese version basically says the same thing. As far as I can tell there's no way to activate the text during regular gameplay. If you check the doll before fighting it, the description is just "?" in both versions. Not to mention the doll that's in the game is floating around the room rather than walking. I took a good look at the enemy text in both versions of the game and didn't see anything unfamiliar, so I doubt the battle data for either of these enemies was actually programmed in.
It's also possible that the little girl was going to be an enemy in the ghost house. There's a townsperson in
Spookane who says "I don't like the little Rosemary girl!", which again is basically the same in the Japanese
version. The Rosemary family you meet in town doesn't have a little girl with them. The use of the name was
probably a reference to the movie Rosemary's Baby, which is about a woman who thinks she is pregnant with a
demonic child. The original plan for the girl might have been for her to either be another random enemy or the
boss and voice that tries to scare the party away as they make their way through the house.
This font can be found in the prototype. The capital letters are a realigned version of the English font from the Japanese version, but the lowercase only exist in the prototype. The capital letters were still used to identify enemies in battle (A-D) but the lowercase went completely unused. Maybe someone didn't like the way this font turned out, or the idea at some point was to implement it during battle.
It's not exactly clear what this round object is, but I couldn't find it anywhere in the game. It sort of looks like it could be a bell meant to be used somewhere in Twinkle Elementary or an earlier version of the well graphic from Magicant.
The first cursor is found at the end of the graphic data for the map. It's a little wider than the arrow that was actually used to show the player's location. The second is only found in the prototype as part of the thin English font set but wasn't actually used anywhere in the script.
The Famicom Family logo and "Nintendo Co. Ltd." text can only be found in the graphic banks of the Japanese version and are with the rest of the graphics for the game's ending. The team probably meant to show those at the end of the credits rolling and just forgot or didn't have time to add them.
Unused items exist in both versions of the game and can be hacked into the inventory.
StoneOrigin - Same effect as the spell.
PoisnNeedle - Same effect as the spell.
IC-Chip - Use not programmed in? In the GBA version, you get an item called "Memory Chip" that takes you back to Eve along with the final note after she's destroyed. IC-Chip is also the name of this unused item in the Famicom version. Lloyd is the only one who can use it in both the prototype and Famicom versions, and the game just gives the "Nothing happened." line no matter how it's used. The player is also prevented from throwing the item away. Because of all this, I think the IC-Chip was originally supposed to have the same function as the Memory Chip.
Frndshp Ring - Still in the prototype; it wasn't just overwritten with the Repel Ring. It still appears to have no use at all.
Map - Still exists as an item in the prototype and functions as normal after giving the translated line "Ninten checked the map."
"Debug" - obviously just placeholder text for blank item values. Value 127 is the only unused item with a description, "......."
TimeMachine - I don't think this was meant to be an item the player could actually have. If you try looking at it the game gives you the "System Error!!!" message instead of just the blank text box of the other unused items. The same thing happens with any other non-item dictionary value you put in the inventory through hacking. This item is listed right after the Real Rocket in the text, so it might have been another planned gag item for the Mysterious Teacher who lives at Twinkle Elementary to sell.
Phil Sandhop: "Memory is definitely hazy, but I think it was a gag item. How to get it, if it was still active is beyond me."
The text from where Queen Mary remembers the final note in the Japanese version was translated but unused in the prototype:
"I am the one who has called you. Ninten, Anna, Lloyd, and Teddy! All of the brave children. Now is the time!"