Isaac Kleiner
Isaac Kleiner is a character from Half-Life who appears in the remix tree alongside Barney. The two of them appear as modified versions of Scratch Cat.
History
Kleiner was present when Gordon drove a flying bus, and told Gordon when he had the correct number code.[1]
Kleiner talked with Barney in a canyon, while Tera and Penguin flew around behind the two of them making noise.[2]