Derek Morgan

Derek Morgan was a mortal who was once the mate of a manticore woman, which resulted in the birth of their hybrid son. Most manticores usually kill their mates after sex, however, Derek managed to escape and did everything he could to find his son. After a collision with Piper Halliwell, he was able to locate and save his son, as well as turn himself back into a normal-looking human. He then left with his son to raise him, and the child was named Damon Morgan.

He has yet to make an appearance in Destined.

Charmed
Through unknown circumstances, Derek became the mate of a female manticore and fathered a child. When the manticore tried to kill him, Derek escaped and became determined to find and free his son. He stole magical supplies to create potions so he would become strong enough to defeat the beasts that took his son. This, in turn, resulted in him becoming a monstrous beast.

When the original Charmed Ones vanquished a manticore in an alley, they found a child and took it home. Derek tracked his son to the manor but was zapped by Wyatt's orb shield, so he instead took Piper.

Derek took Piper to his home and demanded that the child is returned to him. Piper questioned why he wanted the child, though Derek refused to answer. Piper refused to help him, as she believed he was just another demon. She then blasted Derek and tried to escape, only to find that she was trapped in the house by a force field. Piper found a baby rattle and a picture of human-Derek and started to put the pieces together. However, she still refused to help him, and he even threatened to keep her there forever so she would never see her son again.

Derek went to the manor again just as two manticores attacked. He vanquished one and managed to grab his son, but was hit by a potion as he was escaping.

At the house, Piper was finally able to blast through the force field and discovered she was in a suburban neighborhood. She almost left, until she heard Derek and the baby return. As she tended to his wound, Derek explained what happened and Piper realized that he was the child's father. She offered to help, though at that moment, her sisters and the manticores arrived. While the manticores attacked Derek, her sisters orbed Piper home.

Piper told Paige to orb them back immediately, though they were too late. The baby was gone and an injured Derek turned to his human self again. At the manor, Leo healed Derek and the sisters retrieved his son from the manticore lair after vanquishing the pack. Derek was finally reunited with his son and Piper handed him some of Wyatt's old stuff. She offered to bind the baby's powers, though Derek was determined to raise him properly.

Between Charmed and Destined
Derek raised his son in a quiet home, and when the child was around four he started to date again. He eventually married a woman named Annabel Preston, and the two had another son - Daniel. The family moved to Boston years later, and it can only be presumed that they have remained there.

Season 1
Damon mentions him in Little Monster Turns Big.

Physical Appearance
As a young human, Derek was a handsome man with brown hair and brown eyes. He was moderately fit and wore relaxed clothing. As the beast, his whole body was distorted and humped, his face covered in wrinkles and scars.

Powers
As the beast - former
 * Shimmering: The ability to teleport through the use of a "shimmer".
 * Super Strength: The ability to possess enhanced strength much greater than the average human.
 * Force Fields: The ability to create force fields. Derek once used this power to create an electrified shield to trap Piper in his house.
 * Cloaking: The ability to cloak oneself or others. He used this power to cloak his house, preventing anyone from finding him or Piper.
 * Enhanced Hearing: The ability to have enhanced hearing much greater than humans. Derek was able to hear Damon's sonic screams from a vast distance away.
 * High Resistance: The ability to withstand otherwise lethal attacks.

Notes and Trivia

 * Derek is the only known mortal to turn themselves into a magical creature through the use of potions.