This is my first serious pixel art since last January so I'm surprised it turned out this well, though I think I'm still a little rusty.
This was originally from a Pixel Joint contest around Halloween for coloring in these cool monster outlines and adding backgrounds but I never got around to it in time, but I wanted to finish it so I came up with this:

Roughly...3-4 hours of work? Unsure, time flies when you're pixeling.