Tumbaa

Tumba is a miniboss Barf Skag found in the Wildlife Exploitation Preserve usually alongside the miniboss Pimon.

They have been spotted spawning in different areas of the Preserve but typically near the entrance of the Natural Selection Annex (Only available if you have the Gamestop Pre-order or eventual DLC) building on the east side of the Preserve.

Challenges:

Ride Together, Die Together - Kill both Pimon and Tumba within 10 seconds of each other. (+10 Badass Rank)

Trivia

Pimon and Tumba is an easter egg referencing the characters Pumba and Timon from Disney's The Lion King movie.