This is the Worm of Measurement.
He's not an "inchworm" because he has both inches and centimeters on his tummy, see.
See? (According to the Worm of Measurement, I am 24 inches tall and I weigh 13 pounds, 10 ounces. I have no idea how the Worm knows my weight.)
The Worm of Measurement used to belong to Riley. Dad says that over the course of a year, Riley replaced every last bit of his stuffing with her own saliva.
Ba ha ha ha ha!
Saliva stuffing!
If I really understood what that meant, I probably wouldn't be holding the Worm of Measurement at all, let alone chewing on him!
But I don't understand what that means, so ...
Om nom nom nom!