Watch Trailing the Killer Full Movie Free Online 123Movies. While the original title, "Trailing the Killer" isn't a misnomer, it was a bit misleading since the "trailer" is a dog named Caesar (Caesar the Dog) and the killer is a mountain lion. But the makers also pointed out that Caesar "is the most intelligent dog actor since Rin-Tin-Tin" which probably lured a few Rin-Tin-Tin fans with a show-me attitude. Caesar prowls around the woods of the Northwest, dispatches a rattlesnake, visits his she-wolf mate and their pups, pauses to watch the dainty habits of a raccoon personally washing every morsel of food before eating it---and that raccoon had enough food to use up several minutes of running time---and then saves sheepherder Pierre (Francis McDonald)) from getting eaten by one mean mountain lion. Rin-Tin-Tin he ain't, but then who was?