NOTE : I CAN'T PROMISE THIS WILL WORK WITH EVERY MODS!

Mods that currently not supported : 

Iron's Spells 'n Spellbooks
Mowzies Mobs
Mutant Monsters
Aquamirae
Mcreator mods
Any mob that uses brain instead of goal

Usage :
/morph <player> set <entity name> <persistent> (morph to specific mob. set persistent to true will keep morph even if you died)
/morph <player> trigger <goal name> (trigger specific goal of mob)
/morph <player> trigger <goal name> <animation name> (trigger specific goal of mob with specific animation, llibrary/citadel type of mobs must use this)
/morph <player> data <data name> <value> (change entities data, aka EntityDataAccessor. can be true or false, or numbers)

Example :
/morph Dev set minecraft:zombie (morph to zombie, if you don't set persistent, default is false)
/morph Dev trigger cataclysm:ignis Hornzontal_SwingGoal HORIZONTAL_SWING_ATTACK (trigger horizontal swing attack)
/morph Dev data alexscaves:caniac SPIN_SPEED 100.0 (change spinning speed of caniac to 100.0)
/morph Dev data alexscaves:caniac RUNNING true (change running state of caniac to true)

TODO :
kill to aquire morph system with fancy gui (like a original morph mod)
keybind for trigger goals? 
(try this mod instead)
debugging item

Credits :
iChun by original morph mod
Nediamail by mod logo