BIG

Made by his creator, Jay, BIG was built to keep his staff from getting lost in the twisting and confusing architect of the building they all live in. He was even equipped with a hallow chest cavity to store things and people inside safely, and a cage to keep his screen from being caved in (though it can be easily taken off with a power drill). There was even a number of times that BIG was sent out of the confines of the building's walls and out into the world outside, in search for... Someone.
He was fine being just a search bot, working mindlessly alongside his other Batch-mates, until Jay called them in to have some updates; but he wasn't in his right mind.
Things were never right after that night, but he never knew his Batch-mates better.
They had wishes, jobs, wants that he could understand. Big could also understand who built him and what his real purpose was.
He and his Batch-mates had decided that they no longer wanted to work for some old man who was losing himself, so they left the walls for good.

But BIG and B.O.S.S. left something behind.