Date of disappearance: Probably around the 1950s
Reason: Overfishing of tuna and their prey
Special power: The baitballs of herring, mackerel and other prey species they corrall provide a great opportunity for other species, such as dolphins, gannets and other fish-eating birds.
Status: Bluefin tuna are occasionally sighted off Britain today. They need only a reduction in fishing pressure to return in large numbers.