Arachnus in Yo-kai Watch 2

Arachnus is exclusive to Bony Spirits. To befriend Arachnus, the player must first complete the game's main story and unlock the Rank S Yo-kai Watch, after that, receive the version-exclusive quest: "The Bony General" from Arachnus himself at Flatpot Plains. Collect a Bun of Oneness, which are rarely dropped by Chymera at the Infinite Inferno or Kyryn at the Divine Paradise and give it to him, which will make him attack the player due to the unexpected spiciness of the Bun of Oneness. After he battles you, he will be automatically befriended, completing the quest.

Version exclusive: Yo-kai Watch 2 Bony Spirits.