I m making a scp mod and i want to make a custom scp

im making a scp lockdown  expansion mod that adds workers personnel (male and female) and some scps that does not exits in scp mods o other scps that i make up. and there's the problem i made a fox scp (9896) that it's my pet (because i am an scp XD i am Razer Znoerckt) a safe class scp that are foxes that have different colors and names but how i make a entitie that it's tameable,have texture variations and cannot breed because it's looks strange that 2 female fox makes a child and how i make the babies because the baby has adult sounds and how i made the foxes act like minecraft 1.16 foxes (can  sit, sleep in day, attack chickens, defend you) but you can tame it and you can make the fox sit if you don't want the fox attack a chicken but how i made a fox (But you could say that i better made a mod that modifies the foxes but the scp mod is for 1.12.2 and i don't know how to modify entities in minecraft with mods)               and i want make them cry and make strange noises when there's no player (because the foxes like to be with  humans).