Mareep is card #62 of 115 in Unseen Forces (2005), a Common illustrated by Kyoko Umemoto. At about $45.00 it is the #76 most valuable card in the set. In an Unseen Forces booster it turns up about once every 6 packs. It is one of 28 Mareep cards printed so far.
2000Neo Genesis
2003Aquapolis
2005Unseen Forces
2006Dragon Frontiers
2009Platinum
2011Call of Legends
2018Lost Thunder
2021Chilling Reign

















See the full Unseen Forces card list
An ungraded Mareep from Unseen Forces sells for about $45.00. A PSA 10 is worth more, roughly $585 by our estimate, and a PSA 9 around $180.
It is a Common, and it shows up about once every 6 Unseen Forces packs.
Kyoko Umemoto drew the art for this card.
Yes, as a digital simulator. Holobrook lets you open Unseen Forces booster packs in your browser with the set's real pull rates and keep what you pull in a digital binder. No real cards, nothing to buy.