Bella, a 35-lb. mutt, loves chasing rodents. Tarra, 8,500 lbs. of pure Asian elephant, gets her kicks rolling logs. Yet despite these and more significant differences, the two are inseparable. For seven years they’ve romped, rested and eaten together at Hohenwald, Tenn.’s Elephant Sanctuary, a residence for rescued pachyderms. It’s also home to many a stray dog, though normally those with trunks and those without don’t mix. “I’ve never heard of anything like this happening before,” says co-founder Carol Buckley, who recently sold a children’s book on the unlikely union, due in stores next year.

Elephants are social creatures and most of the 17 at Hohenwald have paired off. In 2002 Tarra, a former tire store mascot, was spotted asleep in the grass with new arrival Bella curled next to her massive head. Five years later, when the dog was injured, the elephant stood vigil for two weeks outside the onsite clinic. Granted a visit, Tarra “touched her so gently with her trunk that Bella immediately relaxed,” says Buckley. Now healed, Bella and her big pal, already a hit in a CBS video that went viral on the Internet, may become the subjects of an animated film. Will fame cause a rift? Buckley doubts it. When last seen, “Bella was leaning on Tarra’s foot, getting petted by her trunk.”