Did another page of the Monster Manual before bed yesterday. Page 10, home of the Beholder.
Illuminating the Monster Manual – Page 10
The teenager in me also noted that on page 9 the entry for “Beaver, Giant” has no illustration and has a lot of white space to work with…
Dyson's Dodecahedron 
I feel like they left a blank space for a reason! Summon up your inner Les Claypool for your own illustration, and I’ll comment with my best Frank Drebin impression.
I think I may have said this already on G+, but I think this idea is brilliant. You are like a medieval monk, illuminating a book written by someone else.
“Beaver, Giant”
The mind reels at the possibilities!