Prowlers are a species of carnivorous creatures from the Titanfall series. They are about the size of a large tiger and inhabit multiple planets in the Frontier, posing a formidable threat with their ability to easily maim and kill a human.
While they were present in the first game's concept art and referenced in dialogue, Prowlers did not actually appear in-game until Titanfall 2. They are also seen in Apex Legends, as AI enemies that can be defeated for loot in Bloodhound's Trials on World's Edge and throughout the map on Storm Point.
TF2 and Apex's depictions of Prowlers can be distinguished by their color - in TF2 they are primarily black with yellow markings, while the Apex version is primarily red with blue stripes.