Who is this Salesforce mascot?

That's Earnie Badger.

Earnie was introduced on Salesforce's Official Blog:

How do you see the Trailhead brand? Who are the main characters?

[...] Earnie Badger was made for our community of passionate badge-earners. [...]

That must be Earnie, the new female badger. Heard about her the other day from someone in marketing., but she represents getting badges on Trailhead.

SHE is Earnie, a badger.

She was made for the community of badge-earners.