Sam is the border collie dog of Saige. He is the brother of Rembrandt, her grandmother Mimi's dog. He is named after Sam Savitt, who is known for horse paintings and wrote Saige's favorite how-to art book.
Obviously, don't nominate any human characters. Hybrids like Cheetah or The Lizard are okay, as are shapeshifters with one set animal form (eg Professor McGonagall.)
