Let's Play/Simon Lane makes his feelings about spiders quite clear, and squeals in hysterical fear whenever one appears in a game he and Lewis Brindley are playing. He'll quickly get over it, until another one ambushes him.
Lauchlan of Mix Beer With Liquor lost an eye in childhood, and has developed a crippling fear of becoming blind, or having his vision impaired in any fashion.
Like Ace Ventura and his bat phobia, animal enthusiast Catee Wayne (of "Boxxy" fame) has an inexplicable loathing of geese. The geese episode of "Weird, Gross and Beautiful" is delivered in a flat deadpan with zero interest in the subject matter.
"Sigh. They're really extra-good at nommin' on grass because their beaks are, like, extra-pointy or something. All the better to bite your small children."
Carol Burke, Allen Birkman, and Sierra Manning of Survival of the Fittest v4 all suffer from aquaphobia. In Carol's and Allen's cases, they actually first woke up on the island near the beach, causing them to freak out.
MMORPG Game Masters
After getting his avatar banned because of Real Money Trade, Arthéon can't get anywhere near a Game Master and refuses to call for one when it would the appropriate thing to do.