It does have tons of pieces and I didn't have time to dig the bigger flannelboard out of storage (we are getting ready to shut down our youth services department for a makeover soon) so bear with me.
Here they all are together:
I'm as slow as a ...
I'm as loud as a...
I'm as wild as a ...
I'm as sad as a ...
I'm as happy as a...
My flannelboard pieces were out of 2's Experience: Felt Board Fun by Liz and Dick Wilmes, but I noticed that KizClub has a pattern for this book as well. It doesn't look like they have all the pieces, so you might have to rework the rhyme a bit.
Another fun and faster way to tell this story would be to print out photos or clip art and clip each image to a clothesline as you tell the story. You can also do something similar with a group where each child gets a picture of an animal (some can be repeated) asked the kids questions like "who has a mean animal? a strong one? brave?" etc.
Here's a question for storytime presenters: Do you put all the pieces up and leave them or have one up at a time? I'm a put up and leave 'em girl, especially because this book ends with "Put it all together, it's ME" but I am curious what others are partial to. Part of it would depend on how big your board is also.
*I do express some dubious feelings about the line about being "hot as a fox." Maybe it's just me... but it seems a little odd.