This Loki vinyl figure is released by Funko in their POP! Marvel x What If...? vinyl figure series.
Funko POP! is a crossover vinyl figure series by Funko and other famous franchises such as Disney, Pixar, DC Comics, Marvel Comics, Simpsons, South Park, Uglydoll, etc. Each POP! figure is about ~3" to ~5" tall and crafted in a Japanese anime/manga super-deformed style (NOTE: due to the unique design of each character, the actual size of the figures may be smaller or bigger than stated).
The POP! Marvel x What If...? series features characters from the animated anthology TV series based on the Marvel Comics series of the same name. The series explores alternate timelines in the multiverse that show what would happen if major moments from the MCU films occurred differently.