A Pokedex entry for Cascoon sets you an interesting challenge. This guide on Investigate How Silcoon & Cascoon Differ In Pokemon Legends Arceus tells you everything you need to know to complete this Investigation and work toward filling out the 10 point Pokedex entry for Cascoon’s slide.
A number of Pokemon in Arceus have unique Pokedex entries that require you to complete a specific challenge. In nearly all cases, before you’re able to complete these challenges, you must have caught the Pokemon in question. This particular challenge for Cascoon is tied to two requests Request #1 Wurmple Can Evolve and Request #10 – Wurmples Evolved. Both of these Requests require you to catch a Wurmple to get started. Then you give the Wurmple to the guard during Request #1.
Investigate How Silcoon & Cascoon Differ In Pokemon Legends Arceus
Once the Wurmple has been given to the Guard you need to catch both a Silcoon and a Cascoon. The best way to do this is to catch lots of Wurmples. When Wurmple evolves, at level 7 I believe, it has a 50% chance to evolve into Silcoon and a 50% chance to evolve into Cascoon. Once you have both Pokemon speak to the man again and his Wurmple should evolve, you may need to progress a short way through the story for this to happen. Once this Wurmple evolves and you have caught both a Silcoon and a Cascoon, a new quest will appear asking you to catch one again, but you already have one, so no need.
Simply complete the Request #10 that appears in the professors lab to finish this investigation.