For a Druid theme I can think of two possibilities, you could have the various shapeshift forms:
Cat Form: Black Cat (wow-petopia.com/look/tigerskinblack.html) maybe changed to Hunched Black Cat or Black Saber Cat at a higher level
Bear Form: Black Bear (wow-petopia.com/look/bearskinblack.html)
Travel Form: Orange Spotted Cat (wow-petopia.com/look/tigerskinyellow.html)
Flight Form: Black Hawk (wow-petopia.com/look/stormcrow.html), it even has the ears!
Boomkin, Tree & Aquatic Forms: Nothing really
Or you could go with the various ancients from Hyjal and other areas:
Agamaggan: Armored Brown Boar (wow-petopia.com/look/boarskinbrownarmored.html) or really any Regular or Armored Boar
Goldrinn: Black Saber Worg (wow-petopia.com/look/worgblack.html) or White Worg (wow-petopia.com/look/direwolfskinlightblue.html), sometimes he's black and sometimes he's white
Tortolla: Ghamoo-ra (wow-petopia.com/look/ancientseaturtle.html), if he's a bit difficult at your level try the Green Turtle (wow-petopia.com/look/seaturtleskin.html)
Ursoc & Ursol: Dark Brown Bear (wow-petopia.com/look/bearskindrkbrown.html)
Aviana: No exact match, but perhaps a Ghostly Green Owl (wow-petopia.com/look/owljade_ghost.html) with Ban'thalos replacing it at a higher level
Aessina, Cenarius & Malorne: Nothing really
I've tried to stay within your level range for these, but you may have to die a few times to get some of them (Flight Form is a level 6-7, but it's in Howling Fjord) or head into Horde territory (Travel form is a Northern Barrens rare). Lemme know what you think.