Charging the mound

From BR Bullpen

Charging the mound occurs when a batter takes offense at a pitch that hits him or nearly hits him, and decides to mete out his own justice on the pitcher by running towards him and either punching or wrestling him. This often triggers a bench-clearing brawl. In this situation it is the role of the catcher to come to his pitcher's defence by restraining the batter in any manner possible, and of the umpire to also intervene to prevent someone getting seriously hurt.

Charging the mound will usually result in an ejection of the guilty batter, and can also lead to a fine or suspension depending on the circumstances. The pitcher may also face discipline for throwing a beanball.