The first villain Saitama encounters is Vaccine Man, whose character design resembles Piccolo from the Dragonball and DragonBall Z anime. Christopher Sabat is the English voice actor for both Vaccine Man and Piccolo. Another villain that Saitama comes across in this episode is Marugori, whose character design is very similar to a titan from the series Attack on Titan. Bryce Papenbrook does the voice acting for Marugori, and also for Eren Jaeger from Attack on Titan.