Lagan and Derelict don't actually appear in the novel however, their owner Jay mentions his sidekick after Carlos finds Beelzebub prowling around Nowhere and Evie mentions her parrot. He tells the group that they are 'monsters' now and they no longer fit in their aquarium.
- Lagan and Derelict came from 'baddie' bags given out at Evie's sixth birthday party.
- They are first mentioned in the prologue of the Isle of the Lost, and are mentioned by Jay in Chapter 20, 'Goblin Wharf'.
- Their names are a similar to their parents. Flotsam, Jetsam, Lagan and Derelict are different types of ship-wreck.
- Lagan is goods or wreckage that is lying on the bottom of the ocean, sometimes marked by a buoy, which can be reclaimed.
- Derelict cargo is goods or wreckage also on the bottom of the ocean but has no hope of reclaiming.