I used the Bilbo Transfixed figure that I happened to have lying around:
First, I trimmed down the wrists and sculpted over to look like part of a suit jacket. I then used an elastic band as the trim of the jacket at the wrists.
I then sculpted the over-sized bow tie and once dried, stuck it onto the body.
Next, I sculpted boots over the bare feet, which I did in different stages to stop the chance of me ruining the detail.
Lastly, the longest part was sculpting the has as I couldn't get the right shape. I used a 1p and 2p coin with a wooden rod in the middle as a base and wrapped paper around. I then sculpted over to get the right shape and details.

All that was left was painting:
The green is just a green paint with a green wash.
The red was a red paint with a red wash.
The skin was a base-coat of brown, working up to pink/white then washed with a flesh tone to blend the colours.
The hair was multiple drybrushes of browns and oranges to get the final ginger hair colour.
The gloves and socks was a white basecoat followed by a black wash followed by multiple white drybrushes.
The boots were a black basecoat followed by grey drybrush and the laces are just a dark red.

I like the final outcome.. The hat is a bit large but suits the style of the Mad Hatter.
Let me know what you guys think in the comments :)

(Sorry for the bad quality pictures)