A big swordfish is an abnormally large raw swordfish caught while fishing at any cage/harpoon fishing spot. Since players can only get it while fishing for swordfish, it requires 50 Fishing to obtain. It is a fairly rare catch, and wearing a ring of wealth will not raise the chances of obtaining one. On a sample of 47152 swordfish caught, only 10 were big swordfish, making the chances of obtaining one about 0.02%, similar to the chances of catching a Big shark.
When using the big swordfish on the Taxidermist, she replies, "Don't point that thing at me!" before charging you the required fee.
Previously, if a player attempted to cook a big swordfish they would get the message "You don't have any more swordfish to cook." Now when attempting to cook big swordfish, players will receive the normal XP as if they had cooked a raw swordfish, and they will receive a cooked swordfish as if they had cooked a raw swordfish, as long as they don't burn it.
When dropped next to a normal swordfish, players can see that a big swordfish is actually smaller than a normal swordfish.
If a player catches a big swordfish while helping Frodi, the player will say "Sorry Frodi, but I'm keeping this one" after which Frodi will compliment the player on catching such a magnificent swordfish.