Jaculus

[1] Pliny described it as follows: "The jaculus darts from the branches of trees; and it is not only to our feet that the serpent is formidable, for these fly through the air even, just as though they were hurled from an engine.

This is similar to Malagasy folklore concerning the fandrefiala, identified with Ithycyphus miniatus, a small snake with v-shaped markings on its head resembling a speartip.

After carefully plotting its trajectory with the aid of thrown leaves, the fandrefiala is said to hurl itself at potential victims with enough force to break a metal pot; the impact of this collision inevitably proves fatal to both snake and target.

Yngvars saga viðfǫrla Jämte ett bihang om Ingvarsinskrifterna.

[4] Leonardo da Vinci's notebooks mention an Iaculus who leaps from trees and impales its victims.