I used pine, as I had a 1 x 10 x 4' piece leftover from another project.
Cut two pieces at 18", one piece at 9.25".
To ensure the carvings stand out, you can either stain the entire board or, if you plan to paint only the carvings, put a couple coats of sanding sealer. I went the stain route, with Espresso (I ended up with two coats to get it to my preferred color).
I then used a 60 degree v-carve bit and carved the 18" pieces.
Estimated time: 90 minutes
In all honesty, it would have taken far less time to cut out feet and slimmed the bottom board. However, this does make the bottom and feet out of one solid piece of wood.
I started with a 1/4" spiral bit, then finished with a 1/8" two flute bit. This is the longest carve by far in this project.
Estimated time: 200 minutes
The very thin line on the 18" pieces are used as the 8" cut lines. I ran these through my table saw slimming them down until I got to 8" on each side.
The bottom piece I used the edge of the feet as the cut line.
Once the side rebus pieces were at 8" square, I adjusted the blade to 45 degrees and cut the left and right sides of each piece. This I did for simple glued joinery. Once I had my fence set properly, I cut all the pieces at the same position.
Estimated time: 25 minutes
I then set the pieces on the bottom base and ensured my cuts were accurate.
I glued all the 45 degree miter points and bottom of the rebus sides, then clamped and glued to the base.
After this, a little smoothing sanding and a coat or two of finish.
Estimated time: 30 minutes