The Cat Paw Mug from Starbucks has caused a stir in China. Picture from Twitter

There's a new trend in China and people are willing to fight for it — it's a Cat Paw Mug.

Offered by Starbucks for a limited time only, the campaign went viral and now there are brawls breaking out in Starbucks coffee outlets as people scramble to get their hands on one.

It's a simple, double-walled tumbler but its quirk is that when you pour liquid into it the shape of a cat's paw becomes visible.

The mug went on sale on Tuesday for about R420 ($30) and was sold out within minutes, causing the Starbucks team to re-think the campaign.

CNN reports that after the craze began and the mugs sold out, Starbucks launched an online sale.

The first batch of one thousand mugs made available online sold out within a tenth of a second and now the mugs are only being made available for purchase once daily in the afternoon. 

Watch: People are fighting for #CatPawMugs in China