This is very rare! Whenever you find an NPC with a Prof. Genki outfit, attack him immediately as Prof. Genki drops $300 000 once he is killed! He appears as an enemy on your radar. Note that he has more health than a brute and will run once he sees you. If you attack him, he will fight back and may or may not pull out his stun gun. Bring in at least 1 homie with you when confronting him to make the job easier.