"That pig's head is very big."
Translation:La cabeza de ese cerdo es muy grande.
I got this wrong at first. But clearly 'esa carbeza del cerdo' means 'that head of the pig' which implies more than one head on one pig. I need to be more careful.
The English is ambiguous. It could mean "the head of that pig", or it could mean "that pig's-head". Having just been at a food market in Peru where multiple pigs' heads were on display, I took it to mean the latter and wrote "esa cabeza de cerdo". Is that wrong?