A classic: growing pains. agonizing transformation into giant merman (cw: body horror)

Growing pains, agonizing transformation…It can’t feel good to exponentially grow, legs fusing, limbs distending into a form not suited for land.

Even if he wanted this change, it can’t be pleasant; and it’s exacerbated by not wanting to expose his original form in front of his love interest. What if it feels humiliating?

It’s painful in more ways than one.