I didn't have a precise idea of what kind of animal i could make. But then I came up with these little fellows that I called Papiliches. They're small bird-like creatures, with bright colored hide and wings, like butterflies, and scythe-like forearms. They use them to lock on their prey and then lick their blood.
This image above is a sketch for a color illustration.
Here are the very first ideas : Sparrow/frog shape, round and cute.
But then, they became more anatomically plausible and definitly more creepy.