"Animal Quiz" joke

Animal Quiz
One day the teacher decides to play an animal game. She
holds up a picture of a giraffe and asks if anyone
knows what it is. No one raises their hand.
The teacher says "
See its long neck? What animal has a
long neck?"
Sally holds up her hand and asks, "
Is it a
giraffe?"
"
Very good Sally,"
the teacher replies.
Next she holds up a picture of a zebra. None of the
students holds up their hands. "
See the stripes on this
animal? What animal has stripes?"
Billy holds up his
hand and says, "
It's a zebra."
"
Very good Billy,"
the
teacher replies.
Next she holds up a picture of a deer. None of the
students recognized the animal. "
See the big antlers on
this animal. What animal has horns like this?"
Still no
one guesses.
"
Let me give you another hint, it's something your
mother calls your father."
Johnny shouts out "
I know what it is, it's a horny
bastard!"