question on the doctor with the riddles

Rating: 10/10 (11 March 2005)

what was the answer to the doctor's riddle... the one that went,
"ugly,ugly, fat, fat... in all reality i am yellow and go 'cheep cheep cheep' (or 'quack quack quack'), and when i walk along i go 'poopoo'".
what was the answer??? it's bugging me!
my dad thought the answer might be Adolf Hitler, but i'm not sure.
we couldn't figure it out. it's obviously not a duckling, too obvious.
i don't think the movie ever gives an answer to this
if anyone could help i would much appreciate it
also, i didn't know giosue (the little boy) was in gladiator... why don't i remember this?