Free images results:

Sleepy pictures, stock photos and images


Sleepy Dog Stock Photos
Author: Webmyc
Sleepy Dog Stock Photo
Author: Webmyc
Sleeping Lion Stock Image
Author: Mhd
Cooper Royalty Free Stock Image
Author: Jmcgee

Also, here are some commercial RF-licensed images that match your search criteria:  
Sleepy dog Stock Photography
Author: Mav888