A leak on Twitter by @LlabTooFeR suggests that HTC’s next flagship smartphone will be called Perfume and will run on the yet-to-come Android 6.1 operating system. Apart from this piece of information, he also suggested that the HTC Perfume will be powered by the 8.0 version of the company’s Sense UI.
Remember reports about next HTC's flagship codename HTC O2? It's dead… HTC Perfume is next flagship. Android 6.1 and Sense 8.0_GP…
— LlabTooFeR (@LlabTooFeR) December 8, 2015
@LlabTooFeR had also earlier in the year, dismissed rumours about a Snapdragon 820 powered HTC O2 flagship smartphone, that was supposed to arrive with a 6-inch QHD display, 4GB RAM, 64GB/128GB internal memory, and a 3,500mAh battery.
As of now HTC has not confirmed any details of their upcoming flagship officially, and so all we know about the alleged Perfume is its OS and UI.