OED: The head of a haddock stuffed with the roe, oatmeal, suet, and spices. (Jamieson.)
1815 SCOTT Guy M. xxxii, I gae a look to making the friar's chicken mysell, and to the crappit-heads too. 1816 Antiq. vi, Here is fish and sauce, and crappit-heads. 1861 RAMSAY Remin. Ser. II. 64 ‘Eat crappit heads for supper last night and was the waur o't'.