Is my brother really a dog?

my brother Teddy

we got my brother Teddy from the dog pound so i think we all just assumed he was a mutt. but the more i look at him the more i wonder if he has been hiding his secret identity.  ive never seen another doggy that looks like him... but i did find the photos below. my brother is awesome so i love him no matter what... but i kinda think he might have some cousins he doesnt know about. you be the judge:

 LAMB

FreeDigitalPhotos.net

MOUNTAIN GOAT

Peter Haken / FreeDigitalPhotos.net

LIZARD

markuso / FreeDigitalPhotos.net

KANGAROO

Michelle Meiklejohn / FreeDigitalPhotos.net

FRUIT BAT

Hal Brindley / FreeDigitalPhotos.net