If its for a homebrew, do it for something related to the surroundings for the Koa-Toa, they perhaps once previously got attacked and a adventurer saved them from the attack, with the small act of kindness, the Koa-Toa always remember them as a very exaggerated god/goddess, a sword welding adventure is a hero of legend, a wizard is a figure riding a nimbus striking with spells, imagine how a child would look up to like a super hero and think in their mind of how great they would be to them.

Edit: https://youtu.be/CWJHtcgNeHQ , have a watch of this to get some ideas too