This is likely a nickname for a specific character or a persona (possibly a "Grinch-themed" original character or a specific fandom character like Grima or a "Grinchie" Frenchie).
Could you clarify if is a specific character from a game or the name of an artist you are following? Hooters W! Grinchie
In many fandom communities (like Fire Emblem Heroes ), "W!" often denotes a Winter or Holiday version of a character. This is likely a nickname for a specific