TikTok NPC streams are the latest viral trend. Here's a break down of the bizarre — and lucrative — craze.

• A new TikTok trend has creators acting like non-playable, video game characters — or NPCs.
• NPC streams can be lucrative, as viewers gift creators to control their actions.
• The trend is exemplified by Pinkydoll, who has gone viral in the last few weeks.

It started out with a combination of words that seems a little baffling: "Mmm ice cream so good, mmm ice cream so good, yes, yes, yes, yes, yes, yes," Pinkydoll, a content creator, said during a TikTok livestream. "Yes, yes, yes, gang, gang."

Stripped of context, the video — which went viral on Twitter last week — can feel almost hallucinatory. But it actually represents a growing trend on TikTok that sees creators livestreaming themselves behaving like non-playable video game characters, or NPCs.

NPC streams take inspiration from these virtual characters, who are pre-programmed and exist to populate a game's world. These characters typically repeat the same one or two lines of dialogue, or perform the same actions over and over again.

Creators don't necessarily emulate NPCs from specific games. Instead they reflect this type of character more broadly, engaging in the repetitive set of movements, gestures, expressions, and uttered phrases that have come to define NPCs.

The result is a non-stop loop of activity, during which the streamer is at the whim of their viewers, performing a set of robotic actions that correspond to the digital gifts they receive.

Pinkydoll, whose real name is Fedha Sinon, has inadvertently become the face of NPC streams — and she demonstrates just how much money these creators can rake in.

She told The New York Times that she makes up to $3,000 per stream.

The money is earned through gift tokens that viewers give to the broadcaster, but the whole process is convoluted and requires a number of steps.

Users buy virtual coins through the app with actual money, which can then be used to acquire gift tokens like cartoon roses and pandas. Creators can then convert the tokens they receive into gift coins, which can be exchanged for virtual diamonds. If a creator accumulates $100 worth diamonds, they can exchange them for cash.

A TikTok spokesperson told Insider that the company takes 50% of the net revenue accrued by cashing out virtual gifts.

This transactional process lends itself to NPC streams, as viewers can watch their donations translate to actions in real time.

One of Sinon's catchphrases — "mmm ice cream so good" — is a response to receiving a virtual ice cream cone gift token, for example. While her phrase "yes, yes, yes" is a response to a virtual rose.

Since capturing the attention of the internet last week, Sinon told Insider that her viewership has skyrocketed. Earlier this year, one of her livestreams might have attracted 10,000 concurrent viewers, she said, but now she will garner upwards of 30,000.

But creators looking to emulate Sinon's success are in for a rude awakening if they think it's going to be easy.

"I have mad respect for people who are doing this for more than two hours a day – because it does take a lot of effort," Hayley DeRoche, a TikTok comedian, told The Guardian after experimenting with the format. "You do have to remember what each thing means and respond to it in the exact same way every time."

Others are less enthusiastic about the trend. For every clipped stream that gets posted on Twitter, there's also a critique, with some saying the format cringey or bizarre.

The negative reactions don't bother Sinon.

"Talk bad, talk good," she told Insider. "It's still good promotion."