Jeff sifted through the computer for a few more minutes. He didn't know when his mother was going to come home, but if he was going to try this he'd better give it a shot before his little sister screwed it up.
He paused over lion and clicked on it. Becoming an African lion might be a bit of a problem...
Wait, he though, here's mountain lion.
Mountain lions weren't all that uncommon in these parts, there was a few of them in the hills around town. If the ranchers found them, they'd shoot them, but otherwise people left them alone. And if he was spotted no one would think much of it.
He quickly ran though the settings. He left a lot of stuff random in an effort to beat his sister. He made sure he'd remember who he was, though, and that it would only last a few days.
He found some settings that implied they could alter reality, make it as if he'd never even been born, but stopped. He didn't want to go too far. His sister would be crying to his mother that he'd done something strange, but he could deal with that later.
With the final setting set, he stood in front of the emitter and hit "enter"