The most common and most likely answer to this crossword clue is the 4 plus 4 plus 2 letter word BEAR WITH ME
B
E
A
R
W
I
T
H
M
E
Buddy explains!
The straight part
We know that "How Christopher Robin might describe himself/Hang on" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case how christopher robin might describe himself/hang on = bear with me.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.