Hessians were German soldiers who were hired by the British to fight in the Revolutionary War. While 'Hessians' technically referred to soldiers who were from the state of Hessen-Kassel, it came to be a blanket term for all of the German mercenaries who fought in the Revolution. The imprecision is easy to understand, of course. When a troop of German soldiers lines up and starts firing at you in a war, only the most misguided of geography nerds would stop to ask where they're from. So. Me, then.
Among the Hessian troops who were sent to fight in the American Revolution were at least 2 units referred to as "Jägers." These were light infantry troops, kown for being accurate marksmen. Accurate marksman are very much the best sort of marksmen. The word 'Jäger' also happens to be German for 'hunter', and early members of the Jäger troops were mainly comprised of experienced foresters.
Again - 'really accurate gunmen who are good at fighting in the woods' is exactly the kind of soldier you'd want for a war in the American frontier. Unsurprisingly, this made Jägers the most feared (and respected) divisions of the Hessians.