Riley's idea maker

Add abyss dimension, and multiple new mobs. The abyss crab, rapter, night terror, and the frost hopper. Along with a new terror in the fallow. (did I add a way to get there?) Are the mobs vanilla friendly? Pobably no. A new mob has been discovered in the overworld, the bison. In the nether trapped in a cage, (it is an item) you can also find a toothfairy, but who could have done such a thing and why?