Jessie nicknames him Pirate, or Irish Pirate
Appearance: Since he hasn't hit his growth spurt yet Jack is average height. He's only a few inches taller than Jessie when they first meet. He's thin, though more lanky than actually thin. His hair is rusty red and his right eye is blue. He was born blind in his left eye and it is gray. He always wears an eye patch over it, not because he's ashamed of it but because his mom read about pirates once and Jack decided he wanted an eye patch.
Personality: While Jack isn't in the least bit shy he is quiet most of the time. He is reckless and dives headlong into danger but he won't usually talk about it before he does it. He'll just jump in feet first and with no warning. When he does talk it tends to sound like something random and unexpected, though he has a reason behind everything he says and a logical way he arrived there.
Jack is half British and half Irish. His dad is Irish and his mom British. Most of the time he has a British accent, but when he's nervous or scared he sounds Irish.
Jack is the oldest of his family. He has two younger sisters who are twins - and he's affectionately nicknamed them Squid and Fynn. After he meets the Marshalls he and Jessie become best friends and (for reasons explained in book three) nicknames her Annie.
In spite of being reckless Jack looks reasonable and safe compared to Jessie. This is just his big brother side though. He tried to keep Jessie safe, while at the same time getting her into even more sticky situations than she has ever gotten into on her own.
Jack's dad is an Archaeologist, though he specializes in underwater Archaeology. Jack has plans to follow him in his footsteps, though for the time being he intends to go on a few more life and death adventures with Jessie.
Random Facts: In the original drafts Jack had more than two sisters. I forget the exact count but there were at least four or five. He and Jessie also spent many of the books inventing pirate games and playing them, these are unlikely to appear in the new drafts as they were just there to bring my word count up.
Jack is also the reason Sam is no longer a Marshall. When Jack appeared I realized he was slowly replacing Sam as Jessie's brother and protector.