Ripper roo is a rather unique 'creation' out of all the anthros. He isn't quite an anthro, like the rest. He never was put through the Evolvo-ray. Instead, he was only exposed to the Cortex-Vortex, which ended up having a negative impact on him... he was also the first creation Cortex did on his own.
However, Ripper roo is surprisingly smart underneath his psychotic and insane acts and looks. he is able to read very well for an animal, though he cannot speak. He does occasionally like to annoy many of the X.Treme Island inhabitants though, for the amusement in himself.
Ripper roo is (c) to Activision