A cow catcher is a device attached to the front of a train in order to clear obstacles off the track. Invented in 1838 by British engineer Charles Babbage, the cow catcher is now used mostly in North America, as modern European railway systems tend to be fenced off and less susceptible to the danger of foreign objects on the track. In the locomotive industry, a cow catcher is more commonly referred to as a pilot.

A cow catcher is typically a shallow, V-shaped wedge, designed to deflect objects from the track at a fairly high speed without disrupting the smooth movement of the train. The shape of the cow catcher serves to lift any object on the track and push it to the side, out of the way of the locomotive behind it. The first cow catcher models were constructed of a series of metal bars on a frame, but sheet metal and cast steel models became more popular, as they work more smoothly.

When steam-powered locomotives became more common, the cow catcher was often supplemented with a drop coupler. The front coupler, a device used to attach railroad cars to each other, was fashioned to hinge up and out of the way in order to prevent its catching on obstacles. Another bygone pilot model is the footboard pilot, which featured steps on which railway workers could stand and catch a ride. In the 1960s, these pilots were outlawed and replaced with safer platforms on the front and rear of the locomotive.

Today, people in the railroad industry frown upon the term "cow catcher," but the pilot is still in use. Today's pilots are much smaller and shallower than their predecessors. Since diesel locomotives feature front cabs carrying crew, the pilot must be constructed to prevent the cab from being struck by objects deflected from the road. A separate feature known as an anticlimber is typically installed above the pilot to protect the cab.