Vegan cheese was a bit of a slogan in the Anti-Onision community during the summer of 2011.
Greg uploaded the video "Shiloh Forgot Me" to his channel on June 23, 2011. In the video, he recorded Shiloh having a seizure-like episode and later losing 3 years of her memory. After Shiloh went through a lot of tears and trauma, Greg decided it was important to remind her she was a vegetarian and recorded her eating vegan cheese. (Source) To many viewers, this seemed to be a very strange priority after witnessing what Shiloh went through.
The video received tons of backlash and was soon removed by Greg.
Vegan cheese became a symbol of Greg's seemingly irrational behavior at the time.
A meme was created parodying this bizarre phenomenon called "Dr. Onision". The meme featured Greg with a Photoshopped medical mask and later versions added a stethoscope and a "Hello, my name is: Dr Onision" sticker. No matter what the illness was, he would reply with something that included vegan cheese. The short-lived meme eventually went on to include other strange medical advice Greg had given in his videos and on his social media.
Vegan Cheese and Greg
Greg's intriguing history with vegan cheese.