Marauders is what Harry Potter's father's friend group called themselves.
James - Harry's father - could turn into a stag. Harry was known to look remarkably like his father.
Sirius - Harry's godfather - could turn into a big black dog.
Remus - who had a child Harry became the godfather of - was a werewolf.
Peter - a traitor who helped Voldemort - could turn into a rat.
Every full moon, Remus would go to a safe area. The group would sneak out at night to join Remus, turning into their animal forms, and roam the forest (and make sure that it was done safely to ensure no one came to harm). I suppose in this scenario, your child is the werewolf!
James died when Harry was still a baby. Harry's patronus was a Stag - even though he didn't know that his father could turn into one - and Dumbledore said that his father rode again that night. A patronus glows bright and helps push Dementors (things that make you really depressed and tries to suck your soul out) back.