Ibex or ibis perhaps.
I thought there were other more interesting choices, like Xerus and Urial. I really didn't mind the more esoteric animals, mixed with the common, as I thought it made a good learning experience.
I'd love my boy to point at a red squirrel and (incorrectly) shout Xerus! Xerus! Or (less likely) a mouflon calling it a urial, so I could patiently explain the difference.
Not many; we chose Iguana over Impala because it's more fun for toddlers to speak out "Eee-goo-vaana" with a hand action.
:-)