The rock-crabs, from Vexxarr, are a species that do not eat (they feed on energy gradients), lives in terror of the predators in their native enviroment, and have trouble understanding that other species ever do anything other than running or hiding from danger. They rarely realize that those predators are about the only thing that can harm them. Seetheseexamples of their encounter with a Bleen warfleet.
Stand Still, Stay Silent: Onni Hotakainen has shades of this. Onni is a former scout/mage who no longer scouts because he for some reason was overcome by his fears of the monsters in the woods (being Promoted To Parent for his little sister and cousin may have been a contributing factor too). When the comic rolls around, he hasn't been outside the walls of his home settlement in years. However, Onni is still a mage, and has absolutely no problem with challenging even very powerful spirits in the Spirit realm.
Tyler Marlocke (aka, Moon Shadow) of PS238 is always willing to point out how scared he is in any given situation. This does not stop him from advancing towards sources of danger to help people out. For just one example, he once jumped off of a hovering airplane to save a friend who had just been hit by a Power Nullifier. His mentor, The Revenant, was listening and noted his computer was able to tell the precise height that Tyler jumped from based solely on his screams of fear.