In minecraft bedrock, education and pocket edition there is a glitch when you upload a behavior pack that adds new mobs and if you open a behavior pack then the mobs spawn egg and the mob will be invisble and it will say for an example itemspawnegg enity addon mob.name and when that says that and you spawn that mob then its invisble and it dosent make any sounds.  please update all versions of minecraft including education and pocket edition so that mob addons can be visble and you can see the mob and fix the bug that the mob addons dont make sounds so that they can make sounds