In different cultures, snakes chasing human beings are considered a myth while to others they are a fact. Well, it depends on the snake encountered. It is logical for a snake to chase its prey before catching it. In such a case then it is totally possible and unfortunate that a human can be a prey subject. However, such snakes so large to swallow a whole human are rare to find in normal human settlements. This makes it normal for people in densely populated areas to consider this a myth.
Snake chasing human scenarios
Large constrictors and pit vipers such as the bushmasters are some of the snake species that are capable of displaying such terrifying scenarios. The bushmaster (Lachesis Muta Muta) is venomous and can grow up to 3 meters long. Such snakes will only chase humans as a self-defense effort. Some large constrictors such as pythons and boas are able to swallow young humans. It is a widely known case for snakes to be captured dead after having meals of larger proportions than they can digest so yes it is possible for a snake to munch on a human but not chase them. These large snakes are slow movers and cannot catch up with a running human.
Other reasons why a snake might chase you
For a snake to chase you then one of the following might be the case;