Curiosity

Curiosity is a slang term used for “when this creature deals damage to an opponent, draw a card”. It is named after Curiosity from Exodus, an Aura that grants this ability. Curiosity is a Saboteur ability.

It is primary in blue and secondary in green.

History
Formerly, this ability was called the "Ophidian ability." The slang changed because Ophidian (where the first slang came from) from Weatherlight is technically different in that you have to forego the damage of the creature to draw the card.

The most common variant with this ability is whether or not "combat" is a required hurdle - this allows for ping-granting abilites to draw cards, which are already not common. A rarer variant is to allow the player to draw as many cards as damage dealt - very capable of snowballing. Cold-Eyed Selkie and Glint-Eye Nephilim have this ability innately, while Hunter's Prowess and Hunter's Insight grant it. Diviner Spirit and Xyris, the Writhing Storm have a multiplayer version to allow the damaged player to also draw that many cards.