Okay, so what you have to understand is that Kamen Rider is an ever-changing franchise. Like Power Rangers(new suits, characters, etc per season) or like Transformers.
And X was back in the 70s. And the 70s were weird.
Also, Japan is weird.
So, the Japanese 70s? Weirdest there is.
the gimmick for the monsters in Kamen Rider X was: "Animal+Historical Figure=Victory"