Mystery Mold

Mystery Mold is a key item in Kingdom Hearts. While it has no functional use, it can be sold for a significant amount of munny.

Drops

 * Mystery Mold: Black Fungus (10%)

Strategy
For this strategy to work Sora should already have the Spellbinder keychain which can be obtained after finishing Monstro. Next go to Agrabah, as the Bazaar, which is the first location where Black Fungus can be encountered, can easily be reached from Aladdin's House. It is also a good idea to swap one of the party members for Aladdin, preferably Donald, as Goofy obtains his Cheer ability after finishing Monstro as well.

Once the Black Fungus appear immediately use Summon Simba and charge up his Proud Roar to level 3 or 4 and release it. This will cause all Black Fungus to become dazed causing them to be unable to fight back or turn into stone.

'''IMPORTANT: It is essencial NOT to use Proud Roar level 5 from the start! Proud Roar level 5 will instantly obliterate all the Black Fungus and make them drop nothing but 5 Munny each.'''

After the Black Fungus are dazed there are 2 ways to proceed:

1) It is safe to use Proud Roar level 5 now which will instantly destroy all Black Fungus. Unlike when using level 5 from the start when used as a 2nd attack it won't prevent the Black Fungus from giving their other drops. Apparently apart from the requirement to destroy them with a Critical Hit they must also be struck at least twice.

2) Continue using Proud Roar level 3 or 4 each will count as a Critical Hit and keep the Black Fungus dazed, eventually some should be destroyed and very likely drop some Mystery Goo and perhaps Mystery Mold. Once Simba's MP Gauge is almost empty use Proud Roar level 5 to finish off any Black Fungus that still remains.

This strategy gives approximately 40% chance to get a Mystery Mold from every Black Fungus encounter and 100% chance to get Mystery Goo. Personally I never had a single encounter where Mystery Goo would not drop using this strategy.