Following on from a few previous reports & suggestions, such as #1217 and #1222, I had some suggestions of additions to ModifyEntity's capabilities that would be useful. For example, since certain mobs don't respect the 'stay' or 'sitting' parameters, adding a parameter to ModifyEntity that leashes the mob to the caster would be great- since tameable mob's 'interact_spell' feature prevents use of leads on them. This also happens with nametags, disallowing players to name their pets, in which case a "use_item_name" or "use_wand_name" feature would be great, to set the Mob's name to the name of your held item (as this is already a feature in SpawnEntity)