"I could grow to hate these guys."―Indiana Jones, after his first encounter with Kroeger[src]
In 1933, after Adolf Hitler gave him the task of buy the Crystal Skull of Cozan to French archaeologist René Emile Belloq, Kroeger arrived at the Forteresse Malevil in Marseilles, France in 1933, where he encountered Indiana Jones. Kroeger, whom Jones initially mistook for a Major, was one of Jones' first encounters with Nazis. He mused that he grow to severely dislike them.
Kroeger absconded with the Crystal Skull aboard the U-boat U-357 and escaped from Jones. However en route to Germany, the U-357 struck rocks off the coast of Denmark. Captain Wagner attempted to limp the vessel the rest of the way, but underestimated the amount of damage. The submarine sank, and Kroeger drowned along with Wagner and his crew. Later, when Jones dove to the wreck to retrieve the Crystal Skull aboard, when he opened the outer hatch, Kroeger's dead body fell out.
- Indiana Jones and the Dinosaur Eggs (First appearance)