Megalixir

The Megalixir, also known as Last Elixir, is a recurring item in the Final Fantasy series. It usually completely restores the HP and MP of all allies.

Final Fantasy
The Megalixir only appears in the Dawn of Souls and 20th Anniversary version, and can only be found in the new secret dungeons.

Final Fantasy IV
The Megalixir appears in the Advance release of the game, found in the Cave of Trials and the Lunar Ruins.

Final Fantasy IV: The After Years
Megalixirs are a rare item from Final Fantasy IV: The After Years which fully heal the HP and MP of an entire party. They cannot be bought from shops or received from enemies.

Final Fantasy VI
Betting it in the Coliseum makes the player fight Siegfried.

Final Fantasy VII
In the Northern Crater, the player can find a chest containing a Last Elixir. This is a mistake, as a normal Megalixir is added to the player's inventory instead.

Final Fantasy X
In addition to being a regular item, the Megalixir can also be used through the Mix Overdrive.

Final Fantasy X-2
They cannot be bought from shops but can be sold for 5000 gil.

Final Fantasy XI
The Megalixer will fully restore the user's HP and MP (but not party members). It is only available as a temporary item during certain events such as Besieged.

Final Fantasy XII
The Megalixir is a very rare item, that requires rare loot to make. The only other places they can be obtained are as a reward from the Gilgamesh and Belito hunts and as a rare treasure chest item.