Cerberus is Greek mythology. Not Satanic.
By the way, Cerberus is greek for ‘Spotted”-
IE.. one of the oldest names for a pet in history:
SPOT.
(Who’s a good dog? Spot is! There’s a good boy...)
Actually that's the Romanized form of the Greek name which was "Kerberos" or something similar. And known as "Garmr" in Norse mythology. Seems a lot of folks liked the idea of a terrifying multi-headed dog guarding the gates of Hell.
Although most of them gave the dog three heads, this activity book shows with just one head.
Also, the Harry Potter series had a guard dog with a similar name and three heads who guarded some magical/secret stone.