Golden swordfish eggs

Golden swordfish eggs are a reward from fishing swordfish, used in the Aquarium of a player-owned house. They can be found in two ways:
 * As a rare reward from fishing swordfish (level 70 Fishing required) -- approximately 3 hours on average to get the egg.
 * From the golden mystery egg, which gives you a random fish egg you do not already have, with no Fishing requirement. Golden mystery eggs can be obtained from prawn balls (1/200 chance), or as a 100% reward from using a golden mystery cracker (or having it used on you). One golden mystery egg is also the tier 2 prawn perks reward from the Prawnbroker.

The eggs can be used on the bathysphere in your aquarium to put a swordfish inside the fish tank. Putting it in the tank will unlock one prawn perk, which can be spent at the Prawnbroker