You gain the following benefits:

• While you are wielding a whip, other creatures provoke an opportunity attack from you when they enter the reach you have with that weapon.
• Damage you deal with a whip is especially painful. Creatures have disadvantage when making constitution saving throws for maintaining concentration against damage you deal with a whip
• Once per turn, when you deal damage to a creature with a whip you may reduce its speed by 10 feet until the start of your next turn.