The Actual Team the Fearsome Five never was seen in the animated series, many of its members have. Jinx, Mammoth, and Gizmo appear as H.I.V.E. students, and later members of the H.I.V.E. Five. Dr. Light appeared as a minor villain constantly annoying the Titans. Psimon would also appear in the fifth season capturing Raven for the Brotherhood of Evil. The only member never seen was Mammoth's sister Shimmer.
The Comic Book History of The Fearsome Five
Dr. Light would form the team do to constant losses to the Titans. He would advertise in a super villain's newsletter: The Underworld Star. Psimon would eventually take over as leader and kick Docter Light out. Psimon was a servant of Trigon and made the Team help him, but his failures made Trigon banish him to another dimmension. The members would soon findand save Psimon. The members would later kill Psimon for his alliance with the superhero Moniter. Psimon was alive though and tried to destroy his former teammates, he would attack Gizmo, Mammoth, and Shimmer, but only Shimmer died. A man named Dr.Siavana would reunite the team and revive Shimmer. Dr. Siavana would eventually get fed up with the team and leave them after killing Gizmo. The Last appearance they made was working with the Society of Supervillains before being sent to a Prison Planet.