Mine is Ni Hao, Halloween, Scaredy Pants, Hello-Ween, Cartoon Cartoon Fridays Halloween Party, Garfield's Halloween Adventure and Hoops & Yoyo's Haunted Halloween (Plus Club Penguin: Halloween Panic!).
https://halloweenspecials.fandom.com/wiki/Ni_Hao,_Halloween
https://halloweenspecials.fandom.com/wiki/Scaredy_Pants
https://halloweenspecials.fandom.com/wiki/Cartoon_Cartoon_Fridays_Halloween_Party
https://halloweenspecials.fandom.com/wiki/Hello-ween
https://halloweenspecials.fandom.com/wiki/Garfield's_Halloween_Adventure
https://halloweenspecials.fandom.com/wiki/Hoops_%26_Yoyo%27s_Haunted_Halloween
https://halloweenspecials.fandom.com/wiki/Club_Penguin:_Halloween_Panic!
What is yours?