Lucinda is a pig character created for the 1984 adaptation of the novel The Body in the Library. When Colonel Bantry is brooding, he walks to the Home Farm to see the pigs. Lucinda is a large sow there. Colonel Bantry throws some food to the pigs and watches them for a while, and then says goodbye to Lucinda as he is leaving.
Pigs are also mentioned in the novel, and Colonel Bantry does go to the farm to look at them, but they are not named.