This Katsuki vinyl figure is released by Funko in their POP! Animation x My Hero Academia 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! Animation x My Hero Academia features characters from the popular manga/anime, which follows Izuku Midoriya, a boy born without superpowers in a world where they are the norm, but who still dreams of becoming a superhero himself, and is scouted by the world's greatest hero who shares his powers with Izuku after recognizing his value and enrolls him in a high school for heroes in training.