A proposed evolution for Glocto was based on a kraken/giant octopus, but it lost to Lavoon's blue whale design.
It was suggested that Lavoon be able to evolve through exposure to either a Water Stone or Fire Stone (similar to Scovalope and Bullotus), but in the end it was decided that it should evolve via leveling up.
A further suggestion was that it should only evolve via leveling up while surfing, which this was also eventually rejected.
The Pokédex entry about Lavoon's secretions being collected by humans and used for fuel is a combination of the concepts of collecting ambergris, a greasy secretion produced by sperm whales used to create perfume, and the harvesting of whale blubber to render down to whale oil, which was used as fuel for oil lamps until the early 20th century.
Design origin[]
Lavoon is based on a blue whale. It also continues its previous form's lava lamp theme.
Name origin[]
Lavoon's name is a combination of lava and ooon, an onomatopoeia for whale song. It also evokes the words monsoon, lagoon, or typhoon.