I found these on the web.
http://www.coolest-birthday-cakes.com/monkey-birthday-cake.html#c18
http://www.coolest-birthday-cakes.com/free_cake_decorating_ideas.html#c13
ETA: I have not tried it personally.
Ooh oooh! I did this!! Well, I used the regular 3-D bear pan and chopped the ears off to put them more on the sides so they were where monkey ears are.
http://www.cakegeek.com/images/monkey.jpg
Feel free to PM me if you want more info b/c I'm bad at checking back on posts.
OK, I did it! She was a chunky little monkey, but I think she came out ok! It was my first time playing with fondant (hands, feet, face, ears, belly, bows, bananas and tail) I think I liked the bananas better than the monkey! 
(Thanks cakegeek for the inspiration on this! I think a smaller grass tip would have worked better on the small bear, size-wise - I think that's why she's so chunky looking...(either that or she ate too much the cake she's sitting on! haha! 
) And I learned that I should not use fondant accents on whipped cream icing...too much moisture in the icing and she was sweating, hence the run off of dk brown on her belly, etc. - luckily it was ok, but any longer and she would have been a little mushy mess! Oh well! 'Hannah Banana' loved it! That's what counts!
Anyhow - THANK YOU so much for all the tips and ideas! I learn more and more on every cake and this was no exception! 
Ok - tried attaching pic...too big for forums...here's the link to gallery pic.
http://cakecentral.com/modules.php?name=gallery&file=displayimage&pid=1345072
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