Two particular beings that are not designated as shapeshifters the kitsune and the hellhound have some shapeshifting capacity because of their eye colour change.
Depending on their species, a shapeshifter's transformations can come in any combination, or any order - eye colour, fangs, claws - or any other physical growth or alteration. These said transformations are referred to by fanon as a partial shift - or a full, complete body shapeshift.
The first morphological changes a shapeshifter will undergo will be the change of eye colour. This change occurs in both the internal and external eyesight of a shapeshifter.
Fangs and claws will follow afterwards, particularly under duress. Afterwards, the shapeshifter's complete transformation will manifest will follow up to the point the shapeshifter is capable of.
When shapeshifting, the volume of a shapeshifter's voice amplify. When they speak, there is a new animalistic component added to their dialects. They're capable of issuing animal-esque sounds depending on their species: growls, roars, barks, howls, shrieks and snaps as well as increase the volume and amplitude of their voices. For wendigos and kanimas, their voices become demonic and unnaturally high, most likely due to their unnatural lives.
In a were-creature, initial transformations will be typically unwaranted, uncontrollable. Their first transformations could be triggered in response to emotions such as anger, alarm, shock, or a rapid heartbeat, or their pulse rising.
These uncontrolleable transformations can also occur on a full moon as they are tempered by the moon.
Eventually with practise, focus on an emotional anchor or training under a mentor, were-creatures can completely control their shapeshifting. They can prevent involuntary shifts, learn to change at will, including the order in which the shifts happen. They can manifest their morphological changes at their own choice it being whether only eye colour, claws, or fangs. This will be possible even on a full moon.
Many shapeshifters have the capacity to Evolve. They are able to progress to their next level of development and morph their bodies further, due to a certain process, or character development.
A shapeshifter's ability to transform can be hindered, or prevented, by an outward stimuli. One such physical stimuli could be the appliance of electricity or a supernatural component like an Alpha's Roar. Physical pain also reverse a were-creature transformation and keep them human.