This is the first special and one could say the 0th episode of Shrek: The Series.
A man is walking around with his child dressed as a vampire when a bush moves behind them.
Man: What the...
Three heads pop out.
Man: Son, walk back very very slowly.
The man and son dash away.
Man and Son: Aargh!!!
Farkle, Fergus and Felicia step out.
Farkle: Heh heh.
Shrek and Fiona run up and pick them up.
Shrek: Well kids, you did better than Daddy did when he was 1.
Fiona notices the door is a crack open.
Fiona: Uhh, Shrek...
Shrek: It's probably just Puss or Donkey, or Gingy.
Lord Farquaad laugh is heard.
Shrek turns around to see Donkey, Puss, Gingy, Pinochio, the Three Pigs and Wolfie.
Donkey: Happy Halloween, Shrek!
To Be Continued!