When Reaper catches guests, after a hearty spook when he finds them, he whisks them away to the atrium where they must sit and wait for the game to end.

During Halloween, the Pizzaplex becomes one large attraction where guests are challenged to avoid getting found and caught by Reaper. Most guests either get caught right away, manage to last till the timer ends or opt out of the game.

As you'd imagine, he tends to hide and evade staff when Halloween season ends in an attempt to prolong his active time. He usually manages to reach mid December before his energy reserves finally hit zero.

Some Reaper lore:

He's 15 ft (457.2 cm) tall and is usually only active during Halloween. His preferred method of traversing the Pizzaplex is crawling along the ceiling where he can quietly sneak up on guests (and other animatronics) so he can spook them.