C.ABCBDB
Each stanza of "The Walrus and the Carpenter" follows the same rhyme scheme: ABCBDB
For example, the end words of each line of the first stanza are as follows:
sea, (A)
might: (B)
make (C)
bright-- (B)
was (D)
night. (B)
Since might, bright, and night are the only words that rhyme, that's why it keeps coming back to the B rhyme.