Garfield's Halloween Adventure does not feature any identifiable LGBTQ+ characters or themes. The narrative is entirely focused on a classic Halloween story involving trick-or-treating, spooky encounters, and the antics of Garfield, Odie, and Jon, without any depiction of queer identity.

Garfield's Halloween Adventure is an animated children's special centered on a Halloween night adventure. The film does not include any identifiable transsexual characters or themes, nor does it touch upon gender identity in any capacity. Therefore, its net impact on the portrayal of transsexual characters and themes is N/A.

The movie does not contain any action or adventure elements.

All primary characters in Garfield's Halloween Adventure, including Garfield, Jon, and Odie, maintain their established canonical genders from the comic strip. There are no instances of characters being portrayed as a different gender than their source material.

The film features established characters Garfield, Odie, and Jon Arbuckle. Garfield and Odie are animals, and Jon Arbuckle is consistently depicted as white, aligning with his portrayal in the original comic strip. No characters established as one race in prior canon are portrayed as a different race.