Yoshi Island Spirits

The Yoshi Island Spirits have only appeared in Yoshi Topsy-Turvy to date. Each had a special objective to be cleared before they let Yoshi pass. Their leader appears to be Hongo.

It is unknown if the Spirits have a hierarchy of power among them, or if they reside or have resided anywhere but Yoshi's Island, which is where they currently inhabit. The Spirits include:

Hongo, the Book Spirit
Hongo is the leader of the Yoshi Island Spirits. He is firm and elderly but shows he can be forgiving at times.

Spirit of Cuteness
The Spirit of Cuteness looks like a balloon with wings. She cares about the Egglings and wanted Yoshi to save them.Yoshi had to eat apples to transform the apples back to egglings.

Spirit of Greediness
The Spirit of Greed looks like a golden mouse who has a pocket full of money. To pass him, Yoshi had to collect coins in the level. He had a golden shadow.

Spirit of Mightiness
Also known as the Spirit of Strength, and the Spirit of Mightiness, the Spirit of Power is the strongest of the spirits. He resembles a purple boxer. To clear his levels, Yoshi had to defeat a preset number of enemies. This trial is almost the exact opposite of the Spirit of Happiness'.

Spirit of Scariness
More commonly known as the Spirit of Fright, the Spirit of Fright is a reanimated mummy spirit who's tasks involved racing from rolling spikes.

Spirit of Kindness
The Spirit of Kindness resembles a flower. Her tasks for Yoshi always involved killing the least amount of enemies in a level as possible.

Spirit of Swiftness
Better known as the Spirit of Speed is a Spirit who loves to challenge others to races. She is competitive in a friendly way.

Spirit Who Loves Surprises
The Spirit Who Loves Surprises is a Spirit who was banished from the Spirit Council under the orders of Hongo. He assisted Yoshi throughout Yoshi Topsy-Turvy and hosted mini-games as well.

Speculation
To date, the Spirits have only been in Yoshi Topsy Turvy but some hopeful fans suggest the Spirits could host a future Mario Part, similar to how the Star Spirits which were introduced in Paper Mario went on to be the guides of Mario Party 5. This is mere speculation and no such word has come in any form of an official statement from Nintendo therefore should not be taken seriously.