X-Men #10

Published in March 1965, X-Men #10 serves as a significant milestone in Marvel Comics history, as it marks the first appearance of the villain Kazar, a character inspired by the pulp tradition of Tarzan. The issue was crafted by the iconic creative team of writer Stan Lee and artist Jack Kirby, who were then in the midst of defining the superhero archetype for a new generation of readers. The narrative was designed to expand the scope of the X-Men's world beyond their immediate school environment, introducing a hidden, prehistoric-style jungle located within the Savage Land.

The visual direction for the issue highlights Kirby's dynamic, muscular character design and his ability to render expansive, imaginative landscapes. During this period, the X-Men title was still working to establish a firm audience compared to other Marvel hits like the Fantastic Four, and the introduction of Ka-Zar was a strategic attempt to inject high-adventure stakes into the mutants' ongoing struggle. The issue is generally regarded by collectors as an essential piece of Silver Age history, valued for its foundational role in building the deep lore of the X-Men universe.