AppearanceMorgan is a very tall, intimidating man with white-blond hair and a steel jaw. As his nickname suggests, his right hand is replaced by a huge steel axe, the handle of which seems to go right through his forearm. Like most marines of high rank in the series, he wears a large, billowing coat like a cape. He can also normally be seen smoking a cigar.
Three years ago, Morgan looked much like he does in the present storyline, except without the axe hand and the metal jaw. He was also of a slimmer build than in the present storyline.
PersonalityPrior to "capturing" Kuro, Morgan seemed to be a brave man who was not afraid of death. After his promotion, Morgan was corrupted by his power and became who he is today.
When Morgan is first introduced, he is governing over the small island of Shell Town, where his Naval base is located. He is ruling by fear, abusing his rank to make people pay taxes, and even going as far as killing his own men if they do not obey his commands. He has a very spoiled son named Helmeppo, who is just as bad at using his father's rank to get what he wants from the island's inhabitants. Morgan shows no sort of fatherly love for Helmeppo, even stating that Helmeppo was a worthless son not even worth hitting.
Morgan's obsession with rank is proven in his battle against Luffy, where, despite not being able to to land a single blow on the rubberman (and having taken several), he would not accept defeat.
Pastt is revealed in the Captain Kuro Arc that he was the only survivor in an attack by Kuro on a Marine ship, which left him with a broken jaw. He was hypnotised by Jango into believing that he had captured Kuro (actually a lookalike pirate), gaining him immediate fame and possibly setting him on the path to his current obsession with rank and power. 
Captain Morgan ArcHe was left in charge of a Marine base on an island. As a high ranking and famous Marine, none dared challenge his authority, not even his own men as he had a habit of punishing those who disobeyed him (even killing his own men).
This all changes however when Luffy comes to town to help Koby fulfill his dream, and possibly recruit Roronoa Zoro into his crew. After Luffy accidentally breaks a newly finished statue of Morgan, the captain immediately sets after him (considering that he was about to have one of his men killed for just scratching the statue, this is rather humorous as it occurs just as he was about to do the deed), confronting Luffy in the courtyard of the Marine base. Morgan is defeated by Luffy without even landing a single blow, though he is finished off by Zoro as Luffy has to deal with Helmeppo holding Koby hostage.
Morgan was later seen in the series was in a chapter title page mini-story, as a prisoner stripped of rank on Vice-Admiral Garp's ship, where both Koby and Helmeppo also happen to be serving. However, he slashes Garp and escapes the ship by using his own son as a hostage. Helmeppo disowns him shortly thereafter and returns to the Marine ship, leaving Morgan alone and drifting the ocean.
He was seen again as a cameo in Jango's Mini-arc taking a nap in the ocean as Jango unknowingly passes him.
Major Battles* Vs. Kuro
* Vs. Luffy (with the help of Zoro)
* Vs. Helmeppo and Koby