Items mainly only used for developer purposes probably.

*note* these items will replace your first 7 item slots.

Debug Bomb [7FF88285] - deals 255 damage to all enemies unless attack status is affected (i.e. Geno Boost causes more then 255 damage, having Fear status causes less then 255 damage)
Bane Bomb [7FF883A7] - Causes poison to self or party member.
Doom Bomb [7FF884A8] - Causes 255 damage to self or party member (unless attack status is affected).  If using on self and have less then 255 HP, you remain standing.
Fear Bomb [7FF885A9] - Causes Fear to self or party member.
Sleep Bomb [7FF886AA] - Puts you or party member to sleep.
Mute Bomb [7FF887AB] - Mutes self or party member.
Bomb [7FF888AD] - Deals 255 damage to a single enemy.

Super Mario RPG is cool!