Koopaphobia

Koopaphobia is a persistent fear of Koopas, mentioned only during The Super Mario Bros. Super Show! episode "Raiders of the Lost Mushroom". Indiana Joe is the only known character to have been afflicted with Koopaphobia, as the mere mention of Koopas caused him to shiver uncontrollably. How Indiana Joe developed his Koopaphobia is unknown, although it may be an allusion to Indiana Jones's own fear of snakes.

Indiana Joe was aware of the fact that the legendary Lost Mushroom laid within the Temple of Koopa, but due to his Koopaphobia, he never mustered up the strength to venture inwards, as the entrance itself was shaped like a crowned Koopa's head. Instead, he eventually met up with Mario, Luigi, Princess Toadstool and Toad, and led them to the Temple of Koopa, telling them to enter, while he waited outside.

Indiana Joe was eventually scared off by Kolonel von Koop and the Koopa Pack, and returned to his home. Realizing that he could no longer be a treasure hunter due to his Koopaphobia, Indiana Joe started his own babysitting service. Later, he discovered that the three Mushroom brats he was babysitting were even scarier than Kolonel von Koop himself, and he ultimately overcame his Koopaphobia to help Mario's group recover the Lost Mushroom.

Trivia

 * In Super Paper Mario, when Tippi uses her Tattle ability on any random Koopa Troopa, it is stated that Goombas have a long-held fear, or phobia, of Koopas.