Thank you for all the ideas so far 
To summarize the current proposals (removing / collapsing duplicates):
- Bashful Batagur
- B-Boy Turtle
- Bertie Turtle
- Bulldozer Turtle
- Bountiful Brer
- Bebop Bulldozer
- Baby|Bouncy|Browsing Bowser
- Brilliant …
I think we will like not considered any of the following ones (for the mentioned reason):
- Bionic
- collides with Ubuntu Bionic Beaver
- Breezy
- collides with Ubuntu Breezy Badger
- Blue Box
- similar to ROS Box Turtle
- Bog Turtle
- similar to ROS Box Turtle
- Biomimetic
- complexity of spelling considering international community
- Bodacious | Boisterous
- complexity of spelling considering international community
- Big
- close to the BIG-i robot
If anyone has more ideas please post them soonish. We plan to decide on the name within a week. Thanks!