The Principal of the school may frighten young kids. A nd the punishments he gives may as well.
The kids at school have an extreme hatred toward monsters. They constantly insult them, make fun of them and even threaten them. This could be upsetting to younger viewers.
During a dance-off, Frankie and The King fight over Jenifer. Frankie then slips and falls off the stage onto electrical wiring. He gets electrocuted and briefly seems to be dead. Kids may be stressed and/or frightened before Frankie rises back up and is shown to still be alive.