One Syllable:
* Dog
* Cat
* Bird
* Hog
* Deer
* Whale
* Goat
* Hawk
* Fox
* Bear
Two Syllables:
* Mon-key
* Tig-er
* El-ephant
* Hip-po
* Pan-ther
* Cam-el
* Ra-coon
* Opos-sum
* Wol-ver-ine (three syllables, but many pronounce it with two)
This is not an exhaustive list, just a few examples. The pronunciation of some animal names can vary slightly depending on accent.