This is Evan Dennis, a 19-year-old student at East Tennessee State University.
And this is Dennis's psychology professor, Dr. Chris Dula. Dula is 48 years old and says his class is one of the largest on campus.
On Tuesday, Dennis tweeted out a video compilation of the beginning of his classes with Dula. The professor's lectures start a little bit different to most because Dula lets out a loud, booming "HELLOOOOOOOO" at the start of each one.
People loved the compilation and quickly shared it. So far the video has over 100,000 views and is full of responses from people who wish Dula was their professor.
But Dula told BuzzFeed News his pre-class ritual is just part of living positively – something he has maintained in his life even through illness.
Now Dula posts to his Twitter and YouTube accounts, keeping everyone updated on his cancer treatment.
"People have been kind enough to share my posts and retweet my tweets," said Dula.
"Evan just thought to do his video tweet on his own in support of the effort, and I've been blown away by the reception."