"Great entertainer he is" is a classic copypasta meme used by the SimpleFlips community. The joke subsists off of viewers, used as a way of conveying the point of SimpleFlips being/was in an undesirable moment in mostly SM64 ROM hacks. Material for a new iteration of the meme could bring up Gay Baby Jails, failing to BLJ, dying from lava or quicksand, or just getting screwed over for poor athleticism. Basically, just things that cost the player dearly for their treacherous crimes for just trying to be a skilled player that rewards you for being skilled and then you get two 1-ups and a yoshi coin and happiness.
This joke is probably one of the most free-form of others, because you can combine all of the community's other memes into this format, wrapping it all up into one tight, gay package. Here, look,--
"Finally caught a SImpleFlips stream, he sang 1, 2 Oatmeal for two hours straight, but then lost the vocal skill for "Roxanne". He then proceeded to BLJ the Thwomp's Cock with only half of an "A" press, and fell asleep live on stream, accidentally modding all of the existing Gonzalos in the process. Great entertainer he is!"
In short, it's a format you can use for other SImpleFlips jokes, while knowing that the particular wielding of the words "great entertainer he is" is a joke of the SImpleFlips community on it's own. It's almost somewhat sentimental. ;__;