Thomas went to medical school with Leslie Thompkins, Matt Thorne, and Anne Luitana. Thomas, Leslie, and Matt were known as "The Three Musketeers" at school, and were considered inseparable. They spent their graduation week at the Waldorf, and pictures were taken at a big AMA mixer. They signed their yearbook, "The Caduceus," and remained in touch for several years.
Thomas Wayne once told his son, "Those who have the most, must give the most."
The Waynes' murder would be the single most important event that drove Bruce Wayne to become Batman. Thomas was buried alongside his wife, Martha.
Thomas's son, Bruce, often had nightmares involving his parent's death and this helped continue his crusade as Batman. Bruce would have many photographs and portraits around Wayne Manor and the Batcave of his parents. 
The Thomas Wayne Memorial Free Clinic in Park Row was named for Thomas. After Matt Thorne was arrested for working without a medical license, Bruce Wayne had a friendly conversation with Thorne to learn about his father.
Dreams and Memories
When under control of the Mad Hatter's mind control apparatus, Batman saw a world where his parents had never been killed. In this "Wonderland," Thomas Wayne had retired from Wayne Enterprises, and gave the company to Bruce, who never became Batman. Thomas lived with his wife and son at Wayne Manor, and would often spend his days at the golf course. He was worried about his son's odd demeanor and when Bruce left home, Thomas and Martha contacted the police to bring him back.
While under the influence of the Black Mercy, Bruce relived the night his parents were attacked in Crime Alley, this time Thomas fought off their attacker, until Bruce was freed from the Black Mercy and the dream returned to the familiar nightmare.
- "Nothing to Fear" (in fear toxin-induced hallucinations)
- "The Forgotten" (Cameo in dreams)
- "Two-Face, Part II" (in a nightmare)
- "Beware the Gray Ghost" (flashback)
- "Dreams in Darkness" (in fear toxin-induced hallucinations)
- "Perchance to Dream" (in a mind-control apparatus hallucination)
- "The Strange Secret of Bruce Wayne" (Cameo in Bruce Wayne's memories)
- "Batman: Mask of the Phantasm" (Cameo on portrait of Thomas and Martha Wayne)
- "Gotham in Blue" (Mentioned Only)
- "A Better World" (Mentioned Only)
- "For the Man Who Has Everything" (in the Black Mercy-induced hallucination)
- ↑ 1.0 1.1 1.2 1.3 In Batman: The Animated Series, "Paging the Crime Doctor"
- ↑ 2.0 2.1 2.2 Idem, "Nothing to Fear"
- ↑ The year "1908" is featured prominently in Leslie's yearbook under, although it's relativeness is unknown. As the Batman: The Animated Series episodes take place in the 1990s, it seems unlikely as a birth date and impossible as a graduation date.
- ↑ 4.0 4.1 In Batman: The Animated Series, "The Forgotten"
- ↑ In The New Batman Adventures, "Cold Comfort"
- ↑ 6.0 6.1 In Batman: The Animated Series,"Appointment in Crime Alley"
- ↑ In Batman: Mask of the Phantasm
- ↑ 8.0 8.1 In Batman: The Animated Series, "Two-Face, Part II"
- ↑ Idem, "Dreams in Darkness"
- ↑ Idem, "Perchance to Dream"
- ↑ Idem, "The Strange Secret of Bruce Wayne"
- ↑ In Justice League Unlimited, "For the Man Who Has Everything"