In this Vicious Mockery you actually unleash a string of an insult laced with subtle enchantments at the specific creature which you can able to see within a range. Perhaps, the target able to hear you (though it need not understand you), but it should be succeed on a wisdom saving throw or else take 1d4 psychic damage and also have disadvantage on the nest attack roll which it makes before its next turn ending.
Also read aganazzar’s scorcher spell 5e
At Higher Levels:
Basically this Vicious Mockery 5E spell damage would be increase by 1d4 when you reach to 5th level then the damage would be 2d4, at 11th level (3d4), and at 17th level (4d4).
Attributes Of Vicious Mockery DnD
|Casting Time||1 action|
|Target||A creature you can see and that can hear you within range|