Uxxu

Personality
We do not know much about the character since he is riddled with mystery. However, judging by the way this character is drawn and the way he talks to the characters, he is a very calm, relaxed man. He also appears to be a traditionalist, as he's carrying an ancient wooden staff used to farm mushrooms. Additionally, in the comic he is presented as knowledgeable of mushrooms, and is kind/helpful towards people like Drake Pansymar. He also knows who Mr Farmer, he describes their relationship as such "Mr. Farmer is a good friend of my" - Chapter 1, page 125. 

He has also shown just a little bit that he has a dry sense of humour. Although it was so dry that it sounded more serious than funny.

Skills
As previously stated, he has a lot of information on fungi. He is also a skilled mushroom farmer that uses traditional methods. Because of his extensive knowledge of not only the mushrooms but the place, Shroom Valley, he can identify which mushroom is poisonous, delicious or explosive. He is also good at whistling!

Weakness
It is unknown what his weaknesses are.

The Mystery
There are a lot of questions about the character. For example, Drake Pansymar asks if Uxxu was a man or a mushroom, as he could not tell through the wooden mask basket. Uxxu did not answer, wanting to keep it a secret, as a form of privacy.

In addition, we do not know much about Uxxu's backstory with Mr Farmer apart from being good friends with him.