The Lore tab on the sparrow begins: "The Spider steeples all 20 of his fingers and looks down imperiously from his throne." But the Spider doesn't HAVE 20 fingers! Fallen (Eliksni) have three digits per hand/arm, with four arms total, unlike Humans, Awoken, and presumably Exos, who all have 5 digits on each of two hands. If the latter group were to have four arms instead of two, then 20 "fingers" would be accurate, but for Spider and his species, the total would be 3 fingers times 4 arms equals 12 total.