The Tiny Cabbagehead in Here Be Monsters! An Adventure Involving Magic, Trolls, and Other Creatures; The Ratbridge Chronicles Volume 1

The Tiny Cabbagehead

This little dude is timid at first, but soon becomes BFFs with Titus. First, though, they do some weird cabbagehead-smelling ritual:

Titus leaned forward and took a tiny sniff.

After a moment Titus's face broke into a smile too. He then lowered his face to the tiny cabbagehead and allowed it to smell him. The tiny cabbagehead gave a little squeak and jumped onto his shoulder. (11.50-51)

Must be some greeting or bonding thing.