i had a dream like a week ago where i found out a way to unlock the LAST hidden character in super mario 64 ds, and it was NOT in fact waluigi, but it was instead an ugly 3d rendition of this simba mowgli hybrid from that one jungle book nes bootlet.
the way you unlocked him was that you had to get at least 10,000 coins in the poker game against luigi and if you went into the white door in the character room, you would be sent into the inside of an ominous transparent cube, and then the hidden character himself would pop out and you would have to duel simba yourself, who was unreasonably difficult to beat because he had projectile spam for some reason. whenever you beat him, he would say "may all my rizz be with your gyatt" and then he would explode into the final character key and you could play as him.
if you're wondering how he plays, he just plays like mario, except he could do the twerking animation from the source bootleg on command.