Hero passive transformation

Goal
The goal of this tutorial is to to transform a hero passively (without using an active ability that could be disabled or interrupt his current order), without using the Chaos ability, since it is completely buggy and only usable with regular units.
(see PitzerMike's brilliant Ability Guide for more details)

Method
Say you want to transform a hero, whose unit-type is "Unit Type 1", into "Unit Type 2".

1. You need to create an ability based on Bear Form [Abrf] (though any other permanent transformation probably works too).
2. Then (this is the hard part of this method) put in "Unit Type 1" in the "Alternate Form Unit" field of the spell, and "Unit Type 2" in the "Normal Form Unit", as illustrated in this image:
   
   
   
3. Now, to transform your unit, you just need to add and remove the Bear Form ability to your unit to transform:
   
   Trigger:

   Actions

   Unit - Add Transformation 1->2 to YourUnit
   Unit - Remove Transformation 1->2 from YourUnit
   
4. Your unit is now permanently transformed into "Unit Type 2", and will not morph back at any point without using this method again, or some morphing ability.

How not to fail at using this method

1. Fill out the data fields correctly: the "Normal Form" field is the unit you morph TO, the "Alternate Form" field is the unit you morph FROM.
2. You only need to add and remove the ability: do not set the ability as unavailable for the player owning the unit, or nothing will happen.

Known (minor) bugs
This method can create some weird results in particular circumstances, but they can easily be avoided:

1. If the unit is hexed when you try to transform it, the unit will permanently gain some movement speed. (also named the 1.25 bug)
   This can be avoided by simply checking whether the unit is hexed or not before transforming it. (then use whatever method you see fit to make sure it transforms when it stops being hexed)
2. If the unit you morph to uses animations with a tag (like "alternate"), and the unit is currently idling, it will stay in its base animations (with no tag) until it stops idling.
   This can be avoided by manually adding the tag to the unit.
   
   Trigger:

   Animation - Add the alternate animation tag to YourUnit
   

Excellent ; )

This seems more fitting for the tutorials section, so I'll move the thread into tutorial submissions forum.

I know it's already mentioned in the WC3 ability guide, but a short summary of the problems chaos morph has with heroes or at least a link to the ability guide at the start of this tutorial would be useful, I think.

Other than that, it looks good.

Added a link to the ability guide, since I want to keep the guide as concise as possible.