We tried putting J in several purchased costumes and she screamed and was very unhappy. I don't know if she didn't like the fabric or if she was hot. Anyway, I decided that I would do the costume out of every day clothing/materials so that it would feel like regular clothes and if she got tired of portions of it as the day/night went on I could remove them.
Materials:
Long-sleeved brown onesie, smallest amount of print on the front as you can find (I used this one)
Brown pants of similar material (I used these)
Brown socks (I used some Old Navy socks)
Monkey hat (I used this one, but you could make your own if you wanted)
Brown fabric
White/Beige fuzzy fabric with coordinating thread
Fabric glue
Polyfil
Pink clip (if you have a girl)
Yellow vinyl (for banana)
Instructions:
1. Cut a circle large enough to cover the logo on your onesie out of the white fabric
*I used Word to make sure my circle was perfect with paper and then cut it out of the fabric
2. Sew white circle on front of onesie using zig-zag stitch
*I used this stabilizer on the back of the onesie, which might have made it easier, but was probably unnecessary
*The white fabric I chose melted when I tried to iron it, otherwise I probably would have used an iron-on adhesive and perhaps not have even bothered to sew around the edge
3. Fold brown fabric in half and cut ~1 1/2 inch cane-shaped tube with one edge on the fold (this makes only one seam to sew)
*I did this free-hand, so it doesn't have to be perfect
4. Sew seam of the tail, leaving ~2 inches at the tip open, flip this inside out (use a wooden dowel to help if necessary), fill will polyfil (dowel helps with this too) then finish sewing the tip of the tail by hand
5. Sew end of tail onto back of pants
*If you have a baby that's going to be sitting for a long time another consideration would be to velcro the tail on so that it could be easily removed
6. Cut an oval out of the white fabric that covers half of the size of the baby's foot and then 3 small circles (if you have a bigger-footed baby you could do as many as five small circles)
7. Glue white fabric to bottom of sock in paw-shape
*You could also use fabric adhesive if your fabric permitted
*I have a non-walking child, if she was walking I would probably have sewn these on by hand because the glue didn't work all that well, but it was easy
8. Clip hair on monkey hat with pink hair clip to identify child as girl, if necessaryHere's the final result of just the costume:
9. In order to make the banana I used this pattern with the modifications listed below:
1. The vinyl has a white/beige fuzzy backing, so instead of sewing felt together as she did I just used one piece of fabric which was way easier and I think the vinyl looks banana like
2. I used three pieces for both the banana and the skin (this will make sense if you look at this pattern and is what she suggested as a possible alternative)
I would probably make a slightly smaller banana retrospectively, but I have a smaller baby
Here's my little monkey with her banana
Hope this was useful to someone!