Theo, a mixed-breed puppy, was adopted by Jessica Shyba and her family earlier this month at 8 weeks old, not long after they moved to Santa Cruz.
Shyba, who writes the blog Momma's Gone City, said that the shy puppy had trouble sleeping alone and quickly made it clear he wanted company at night.
After a few days, he began to join Shyba's youngest son, Beau, in his daily naps, and the two began to form "the most organic and beautiful friendship I have ever witnessed," Shyba wrote on her blog.
Shyba began posting photos of the two young friends on Instagram and then on Thursday posted a number of them to her blog. "Each day, Theo meets us at naptime and waits patiently for Beau to fall asleep," Shyba said. "By that time, he's also sleepy, so when I hoist him on to our bed, he stumbles over to Beau and plops right down on top of him. And there they sleep, entwined, for at least two hours."
The photos have rapidly gone viral and been featured on sites including Huffington Post and Yahoo and on shows such as ABC News and Good Morning, according to SPCA officials.
The photos have also gained their own hashtag, #theoandbeau.
Theo was part of a litter of 11 puppies rescued by the SPCA. The Shyba family is encouraging those who enjoy his photos and story to consider donating to the Santa Cruz SPCA, officials said.
The photos can be seen at mommasgonecity.com/2013/11/wishes-granted-theo-and-beau/.