pJennifer Arellano uploaded this video of her substitute teacher ‘Mr K,’ after hearing of his untimely passing due to cancer. In the video, Mr K amuses the class with a self-deprecating ‘rap’ as he introduces himself. Arellano wrote a heartfelt tribute in the video description, calling Mr K “the greatest substitute teacher to walk any halls of the KSD.” With nearly 100,000 views already, it looks as though many others felt the same way.