Lucius Fox is a young man in his thirties, with black hair, brown eyes, black skin and a black mustache. He wears some black framed glasses, with a light blue shirt and magenta tie, with an orange sweater and slate grey blazer over top.
He is voiced by Phil LaMarr in the English version of the cartoon.
In Welcome to Super Hero High, Mr. Fox makes a background appearance inside Super Hero High School standing with Barbara Gordon after Poison Ivy opens the front doors while Principal Waller introduces the school for a promotional video.
In Weaponomics, he grades students during a Weaponomics class as they show off their weapons. When he holds an apple for Wonder Woman's demonstration of her Lasso of Truth, the Cheetah sabotages the demonstration and he gets caught in the Lasso, getting compelled to share embarrassing secrets. After Wonder Woman frees him, he gives Wonder Woman detention for losing control of her weapon.
In Saving the Day, he gets caught onto the amethyst at the top of Super Hero High after taking his invisible jetpack for a test run, and is left dangling from the jetpack, triggering the Save the Day Alarm. Wonder Woman, Bumblebee, Harley Quinn and Poison Ivy arrive outside the school to respond to the alarm, and are informed of this by Principal Waller. They work together to save him under Wonder Woman's leadership, with Bumblebee freeing him from the jetpack's straps and Harley Quinn cushioning his fall with a giant whoopie cushion. After the rescue, the Cheetah appears climbing the amethyst saying she was going to rescue him, before falling off. When Wonder Woman uses her Lasso to save her, she reveals that she sabotaged his jetpack to save him herself and win Hero of the Month, along with many other misdeeds against Wonder Woman, including sabotaging her Weaponomics demo in "Weaponomics". He later leaves with Principal Waller as she is given detention.
In Hero of the Month: Harley Quinn, Mr. Fox appears in archive footage from "Saving the Day" in Harley Quinn's Hero of the Month VT, having his fall cushioned by her giant inflatable whoopie cushion. In The Ultimate Accessory, he gives instructions to a Weaponomics class for the midterm project to "create a high tech accessory that would aid [the student] in a fight". Later, he watches a fight at the docks between Miss Martian, Harley Quinn and Katana, each using one of Bumblebee's midterm accessories against King Shark. After Bumblebee and her friends successfully defeat King Shark with help from the accessories, he give Bumblebee an "A" for "technology, technique and teamwork".
In For Art's Sake, Mr. Fox makes a non-speaking cameo appearance attending the SHHS Student Art Show Fundraiser in the school foyer as Silver St. Cloud's painting is stolen by the Double Dare Twins. In It's a Superful Life, he attends the SHHS winter holiday tree ceremony in the school foyer and stands by the other faculty as Principal Waller wishes "Happy Holidays" to the students.
In Ha-Ha Horticulture, Mr. Fox appears sleeping outside the school along with most of the rest of the students and staff due to Poison Ivy's sleeping poppy experiment. Later, he appears as Harley Quinn and Ivy distribute pollen across the school to undo the effects of the poppy. In Truth of the Lasso Part 1, he enters his office one night as Wonder Woman and Bumblebee catch the Cheetah stealing midterm answers. Compelled by Wonder Woman's Lasso of Truth, the Cheetah admits to it as well as that she does so for every test. As he is about to give her one month of detention, she admits via the Lasso that she thinks his sweater vest is nerdy, causing him to extend her detention to two months. He then thanks Wonder Woman for her assistance. In Fly By Night, he exits his office at night after finishing semester grading while talking on the phone, saying he will be at the dance club soon for rumba night as Hawkgirl helps Wonder Woman and Bumblebee sneak through the halls past him after curfew to retrieve their Phys Ed project from the cafeteria.