Fear Les
It’s possible the person’s name is Les and they’re warning people to fear them. It’s also possible Les is someone else that needs to be feared. But why put a heart after the warning?
It makes much more sense for the tattoo client to have just made a gross error in writing “fearless,” which wasn’t caught by the artist. It’s almost like they thought the word had only one “s” and needed the heart to take the place of a letter on the last finger.