A Death Eater, the father of Vincent Crabbe. Like his son, Mr. Crabbe is a large fellow — one of the two largest Death Eaters to attend Voldemort’s ‘rebirthing party’ — and a bit dim (GF33, OP26). Mr. Crabbe is most likely the Death Eater whose head got turned into a baby’s.
Crabbe=“Krabben” Low Ger. ‘to scratch, claw.’ To be crabby is to be bad-tempered and combative, or to complain irritably (OED).