U-1146 (Patreon)

Fanart of a famous manga 《 はたらく細胞 》aka "Cells at work!".

He is a White Blood Cell, specifically a Neutrophil (好中球, Kōchūkyū), working under the Neutrophil Division. Along with the other neutrophil comrades, he's tasked to patrol around the Blood Vessel and remove any invading Foreign Cells or Germs. Due to his violent job, he's often seen stained in blood after killing Foreign Cells or Germs.   

Trivia: The "46" in his number can be read in goroawase as "shiro", meaning "white" in Japanese.