Several Fear the Walking Dead crossover characters from The Walking Dead appeared in the spin-off, including some of the parent show’s main characters. When The Walking Dead‘s short first season aired on AMC in 2010, it earned raves and high viewership numbers, which only increased as the seasons went on. By the end of season 5, The Walking Dead was hitting its highest levels yet, leading AMC to launch the prequel series Fear the Walking Dead. While Fear the Walking Dead had its own cast of characters which it followed at the start of the zombie apocalypse, it wasn’t long before characters from The Walking Dead crossed over.

https://screenrant.com/walking-dead-fear-crossovers-every-character/