Letter Bb!
Big B, little b!

Bear, Bear, make me a boat.
Boom! Bang! Bonk!
Bear, Bear, jump into my boat.
Boing! Boing! Bonk!

Bear, Bear, make me a bed.
Boom! Bang! Bonk!
Bear, Bear, jump onto my bed.
Boing! Boing! Bonk!

bear
boat
bed
bus

Bear, Bear, make me a bus.
Boom! Bang! Bonk!
Bear, Bear, jump into my bus.
Boing! Boing! Bonk!

/b/ is the sound of Bb.