Question: Baruffio and the buffalo

[nkafkafi]

No: HPFGUIDX 90118

Since English is not my mother tongue, I always suspect I'm missing 
puns and clues in HP. It took me two years to realize there is a pun 
in "Diagon Alley" <hang head in shame>. Now, could someone please 
explain to me (slowly, with diagrams) if there is a pun in:

SS/PS, Ch. 10:
"Now, don't forget that nice wrist movement we've been practicing!" 
squeaked Professor Flitwick, perched on top of his pile of books as 
usual. "Swish and flick, remember, swish and flick. And saying the 
magic words properly is very important, too – never forget Wizard 
Baruffio, who said `s' instead of `f' and found himself on the floor 
with a buffalo on his chest."

I would have thought that the editors got it mixed up as usual and it 
actually should have written "said `f' instead of `s' ", but what the 
@$#& is a "bussalo"??? Do we need a Latin expert here?

Thanks,
Neri