Ashes of the Abhorrent Ashes of the Abhorrent might be too narrow an answer
Prices are updated based upon Magic War of the Spark listings that sold on eBay and other marketplaces
Every land you play adds a +1/+1 counter, so this 1-drop steadily grows into a real threat
Although this card is technically a humble Uncommon, its age, first edition stamp, and status as an Eeveelution ensure that it commands an impressive value, even if it can't compete with some of its kin to come
While you can choose which effect is activated, the card itself can only be used when you control no cards, making it most useful in the early game and a potential dead draw later on
While the number of sales evened out soon after, that initial burst of demand set off a price run thats still going today