Dillus the Bearded
According to the giant Ysbaddaden, who assigned Culhwch this task, the beard had to be plucked while Dillus was alive, and Dillus naturally would likely not take kindly to the procedure. Arthurís warriors Cei and Bedwyr found Dillus in Pumlumon.
They waited for him to eat his fill of a pig and to go to sleep. When he was asleep, the two warriors plucked his beard with tweezers and then killed him.