The Whistler
The Whistler is a monster born from when the universe was first forged. Screaming in pain and agony as it took shape. What drew it to Runeterra is a complete mystery, but most say much like his ten other brethren they were summoned once in the distant past and from there became nothing but myth.
Unlike his other sibling the Fiddlesticks who represents humanities fear of itself, the Whistler is the amalgamation of what all creatures fear goes thump in the dark. It's said he grew more powerful as more and more stories were told of him soothsayer magics flowing into his once intangible form giving him shape of long lengthy arms, thousands of teeth kept hidden inside skin as dark as the night. And his eyes a piercing glowing shade of purple that for many is the last that they see.
Across Ionia when entire villages go missing without a trace it's often blamed on a whistling noise deep in the dark.
OP note:
Finally taking the time to rework this big boi really need to make the refrence for his mouth parts but his new anatomy takes far more refrence to bats and frogs. Compared to the before bird look he had