Cave Johnson is a fictional character from the
Portal franchise first introduced in the 2011 video game
Portal 2. He is voiced by American actor
J. K. Simmons and created in part by
Portal 2s designer
Erik Wolpaw. He is referenced by a computer username in the
first game and appears indirectly in
Portal 2. Johnson serves as a guide to the player-character
Chell as she explores an abandoned part of the
Aperture Science facility, though all of his messages are pre-recorded from before the events of the
Portal games.