Black Fungus

The Black Fungus (ブラックファンガス) is an Emblem Heartless from Kingdom Hearts. Unlike the other Mushroom Heartless, it is very aggressive. It can turn into stone to defend itself and release poisonous gases, making it very hard to defeat. If you finish them off with a critical hit at the end of a combo, they may either drop a Mystery Goo (100%), or a Mystery Mold (10%). It is possible for them to drop both, and upon being finished with a Critical Hit, they drop around 20 to 100 Munny.

Kingdom Hearts

 * Agrabah
 * Halloween Town
 * Hollow Bastion
 * End of the World

Kingdom Hearts: Chain of Memories

 * Black Room

Kingdom Hearts
''Hostile Heartless, unlike White Mushrooms. They attack with poison. Defeating them may bring good things, but it is not easy.''

Kingdom Hearts: Chain of Memories
An aggressive, poisonous Heartless, not to be confused with the White Mushroom.

The Black Fungus likes to paralyze its foes and toy with them.

It's tough to beat, but victory doesn't go unrewarded...

Mystery Mold
The Mystery Mold is an item obtained from Black Fungi in Kingdom Hearts. In order to obtain it, you must defeat a Black Fungus with a Critical Hit. It has no purpose except bragging rights, though it can be resold for 9999 Munny.

Strategy
If you're having trouble finding Mystery Goo when you find a Black Fungus, use Trinity Limit. If you don't have Trinity Limit yet, use Gravity, as it is usually a one-hit knockout. Since the Black Fungus drop Mystery Goo after critical hits, make sure to remove all Combo Pluses before you fight them to shorten the length of your combo.

In Kingdom Hearts: Chain of Memories and Kingdom Hearts Re:Chain of Memories, defeating Black Fungi usually gives you a Calm Bounty card, so exhausting Black Room cards is a rather easy way to stock up on Calm Bounty cards.