When Lola is worried about starting school, her older brother Charlie reassures her.
Schools -- Fiction.
Friendship -- Fiction.
Hayes, Abby (Fictitious character) -- Fiction.
Families -- Fiction.
When Freddy's mother finally allows him to bring Harold, the class hamster, home for the weekend, Freddy has his hands full making sure that Harold does not escape.
Gerald the elephant tries to tell Piggie that ball-throwing is serious business, but Piggie just wants to have fun.
Experiments -- Fiction.
Fear of the dark -- Fiction.
Radio and television novels.
Sid the Science Kid (Fictitious character) -- Fiction.