Could you please elaborate? Tell me their health, their size, their speed, their behaviour, what they drop, what their drops do, whether they attack, their attack damage, how they attack, if they are tamable, how you tame them, what they do when tamed, and most importantly, why they should be added. Don't just tell me, put it in the OP. (There's an edit button, you know.)
("why not"/"because I want to" are not valid reasons. "let Mojangcrasoft decide" is lazy.)
Please give a more detailed response.
(Also, "more tamable mobs" is largely frowned upon. Any new tamable mobs need a use.)