A key issue noted for First appearance of Ysengrin. Teenage Mutant Ninja Turtles: Nightwatcher #4 was published by IDW Publishing on December 1, 2024, as part of a series that began in 2024. Juni Ba writes, and art comes from Fernando Peniche, Jon Lankry and Luis Antonio Delgado. This 32-page issue features Jennika, Hieronymus Hale and Ysengrin.