I'm not sure exactly what this creature is but it sure is cute! Really nice sharp shot of it. Love the childish writing since it's for a children's zoo, nice touch. I don't think the choice of colour for the border works though.
Awful colors (to me) but they totally work in your super cute photo. Boy, I can almost smell the reek of that zoo water! ;>) Your choice of lettering is also a nice touch. Bumping to 10
What an odd looking fellow this is - and a great choice for your poster, since kids really would find this guy fascinating! I also very much like your choice of font for this.