|Name (transcribed): #j.#|
Identifier (HEX): 00
Identifier (DEC): 000
Effect pointer: 00:01d1 (ROM 0)
Unterminated name glitch item?: No
Buy Price: 829850
Sell Price: 414925
Name bytes: $17, $a9, $5f, $22, $50
Using will typically freeze the game both from inside and outside of battle.
It is a common item in the expanded item pack.
The inventory can also be filled with this glitch item with the j. (0x00) inventory filling map script glitch.
More accurately, this glitch item runs in the middle of two byte map header pointers (these begin at $01AE) at $01D1; misaligned in between Route 6 and Route 7's header pointer (executed as instructions; not followed). When the code is in between Route 10 and Route 11's header pointers, it represents call nc, $BE42. The carry flag is not set; hence $BE42 is executed.
SRAM may be locked resulting in the typical "rst 38 freeze", but can be avoided if the player views the summary of a Pokémon from the party just before using the item, allowing for arbitrary code execution at 00:BE42. Using a pop hl at the end of the code, the stack can be manipulated to safely ret.
While theoretically possible, methods to write to 00:BE42 and use with the corrupted values have not been published yet.