Really fun illustration, I love the details and grodiness of the monster, and you've got a really good range of values on the guy too. Also he is framed really well with the dark mass behind him.

The big thing holding this piece back though is the presentation. Just cropping it and getting that pen out of the frame would put the focus on the art itself without any extraneous clutter,
The focus should be on the art, not on the utensils.
That being said the bright yellow at the top does look really nice with the dark blue, but being that its so divorced from the piece itself it's not being used to its full potential. Maybe pulling that yellow in to frame the monster, or to fill in the white circles on the dark mass would help in bringing it all together more. The little scribbles around should also be gotten rid of, in ms paint you can just crop some of the surrounding paper and copy/paste it over, if you don't have Photoshop or a better photo editing program.

Your work is really good, well rendered and framed all around, and it deserves the best presentation you can give it. Spending that extra time to get a perfectly straight photo, cropping it correctly, maybe adjusting the lighting and contrasts in post, and/or making sure the art is the sole focus are small sometimes tedious things that help do your art the most possible justice.