Huh, there's a Wario Land 4 character pack for Mario 64...

[CM30]

Didn't expect someone to actually make Wario the main character, add Keyser as a pet and add the remastered Wario Land 4 tracks as music replacements:

Wario Land 4x64 Pack

This is a small collection of Wario Land 4 mods for Super Mario 64 Coop DX! If you don't want to use a part of the modpack, just delete the other folders (or don't enable them). Pack Includes: Wario Land 4 Skin (Custom Model by Mariofan2468)...

mods.sm64coopdx.com

 

[Really Ilini]

Wow, that Wario model is a spot on translation from his appearance in 4. Great texture work.