Both are correct, but the choice depends on context:
* "Spooky season" (no article) → Used as a general term, like a name or phrase.
* "Spooky season is my favorite time of year."
* "Get ready for spooky season!"
* "The spooky season" → Refers to a specific or known period (e.g., Halloween time).
* "The spooky season is here!"
* "I love the decorations during the spooky season."
If in doubt, "spooky season" (without "the") is more common in casual use.