My fuzzy widdle bug-eating forebear. (Illustration from Leary et al.)

Protungulatum donnae--or Aunt and Uncle Protty, as I'm sure they'd prefer to be called--weighed less than a quarter of a kilogram soaking wet, and were adapted for tickling you with their dextrous little paws. Their babies were born one at a time, blind and hairless and cute as prehistoric buttons. It was a jungle out there for our poor Aunt and Uncle, dodging the giant clumsy feet of their massive reptilian neighbours; the world was wild and dangerous, and they were small and defenceless.

But they were also survivors: unlike their mammal contemporaries, they were not annihilated by the asteroid that took out the dinosaurs. "Huzzah, more bugs for us!" they likely squeaked as they scampered over the corpses of the dead and up into the trees to fill their wee tummies with grubs and aphids.

And they didn't stay in those trees, oh no! They got slightly bigger, invented language, and began a project of bending the Earth to their will. So sick of getting stepped on, they thought, grinding their three sets of molars together in bitter recollection, Watch out, world. Now it's our turn. 

I think you have Aunt Protty's eyes, and maybe her separate anal and urogenital openings.