Frankie Stein, an established original character previously female with she/her pronouns, is explicitly non-binary using they/them, with voice actor iris menas (non-binary) and repeated on-screen pronoun introductions normalized as casual inclusivity. Showrunner Shea Fontana stated the intent to "expand the range for the kind of kids that see themselves represented" and consulted non-binary crew for authenticity, with full Nickelodeon/Mattel support. Episodes reinforce this via acceptance arcs: Clawdeen's Were-Ruler role challenges traditional were-world norms; "Humans in High School" corrects monster misconceptions about humans; "Fired Up" centers climate activism competition; anxiety, mentorship, and self-acceptance stories layer identity exploration.

The franchise's "be yourself, be unique, be a monster" slogan and GLAAD Pride tie-ins frame diversity as the core appeal. As children's media, these elements carry amplified weight, prioritizing modern social justice framing over traditional monster lore. Reception shows polarized backlash labeling changes "forced," while supporters highlight trans joy and generational prejudice-breaking. The ideology drives character arcs and messaging without collapsing every plot, but remains foundational rather than incidental.