These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Complete Monster: The Creeper; before he arrived, all characters in the show had at least once displayed a softer side, and the worst you could get was a greedy yet harmless tiger who beside having some jerk moments wasn't really evil. The Creeper, on the other hand, has no redeeming qualities, and is actually willingly to damage the Core and Animalia for his personal ambitions. His schemes included trying to start a war on Animalia, kidnap a child, and trick the protagonist and Livingstone in falling to their death when Livingstone offered to forgive him for his fault. He steals precious possessions from everybody just because he enjoys doing so. And as if it wasn't enough, he is also an Omnicidal Maniac wannabe...
Creepy Awesome: The Creeper, again. Despite being the nastiest character in the show, fans love him.
The Woobie: Fuschia, for having to put up with Tyrannicus.
Alex also has his moments.
They Wasted a Perfectly Good Plot: the finale episode reveals the Creeper used to be the King of Animalia as well as a friend of Livingstone until he got Drunk with Power and became an outcast. This is only mentionned for a few minutes sadly, and is never really developped.
Also, the war in Animalia plot could have been an interesting potential story arc, but is instead solved in just one episode. Granted, from the story's perspective, this was a good thing.