Jared realized that he could make his child (which, he found when he checked, was a boy) older. It would be impossible to hide a crying baby, but if his son was older, he might be able to hide.
Which had two problems. First, Jared didn't know how much his son's mind would change. When he became a dog he was something like one, but not completely. Second, even if he aged him he'd still be a kid, and kids certainly had ways of getting into trouble.
Jared found a package of socks that he had never opened and took one out. Putting the medallion around his infant son's head, he touched it to the sock and the baby started getting older. He normally would have gotten old enough to wear the sock, but when the boy was around 8 years old, Jared took the medallion off and the boy stopped growing older.
"What do you remember?" Jared asked his son.
"Nothing," replied the boy. "I remember things were dark and then light, but I didn't know how to do anything."
"I think you're remembering the birth," said Jared.
"I think I am, Mom," said the boy. "Mom?"
"I'm a guy! It's strange to call me that!"
"But I know that you're my Mom. Mom, I don't have a name. Could you give me a name?"
"Hmm. I don't know. What about... Jay?"
"That's a nice name, Mom."
"Jay," said Jared, "I need you to do something. It's very important." He hoped that Jay wouldn't choose this moment to start being bratty, which he knew would happen sooner or later.
"Yes, Mom."
"I'm not Mom! I'm a guy! Well, I guess I am your Mom, but don't call me that in front of anyone. Now what I need you to do is this. Mom and Dad... your grandparents... are coming home in an hour. You need to be utterly quiet. Pretend that you're not here and hide. Either in my closet, or under my bed, or someplace, but it has to be a place you can't be seen or heard."
"I don't want to, Mom! I want to see my grandparents. I never have!"
"You can't be seen because a few days ago you didn't exist. You're only here because I used my magic medallion. Mom and Dad would think it strange if they went away and came back and I had an 8 year old son."
The boy looked at the floor and seemed to think about it for a second, then said "All right."
Jared left Jay downstairs and climbed into the attic to search through some old suitcases. He managed to find some clothes he had worn years and years ago--which would be perfect for Jay, so at least he didn't have to go naked. He came back down and let Jay dress, then took Jay into his room. "Now, as soon as Mom and Dad get back, you have to hide..."
An hour later his parents got back. Miraculously, Jay had obeyed Jared and did not run out into the open. Jared locked the door to his room, turned on some music, and played video games with his newly existing son, who knew nothing about them--apparently video games weren't as essential a part of someone's mind as peeing on trees was to a dog or talking was to a human, and the medallion didn't make him know how to play them.
They managed to make it through the night without Jay causing trouble. The next day was Saturday and Jay stayed hidden. At least for a while. Jared looked at his clock and the 12 hours were up. Then....