Delta Species is a set in the EX series. It was released on October 31, 2005. The printed size is 113. This checklist is longer, at 114 cards. Ditto is 40/113, in position 40 of 114 on this checklist. Before it is 39 Ditto, and after it is 41 Dragonair δ. The listed rarity is Uncommon.
Ditto is a Basic Water Pokémon with 60 HP. In the Pokédex this is Ditto (#132), generation 1 (Kanto).
Yuka Morii illustrated this card. The same name is on 204 other cards in the catalog.
Ditto (#132) has 31 other cards in the catalog. Those other cards are in 20 sets. The other printings with a release date run from 1999 to 2026. The earliest other card is Ditto 3/62 in Fossil (1999). That card lists 50 HP, and this one lists 60 HP. The rarity there is Rare Holo, and here it is Uncommon. Keiji Kinebuchi illustrated that card, and Yuka Morii illustrated this one. 16 other cards of Ditto list a different HP.
Duplicate is listed as Poké-Power. Once during your turn (before your attack), you may search your deck for another Ditto and switch it with Ditto. (Any cards attached to Ditto, damage counters, Special Conditions, and effects on it are now on the new Pokémon.) If you do, put Ditto on top of your deck. Shuffle your deck afterward. You can't use more than 1 Duplicate Poké-Power each turn. The attack Smash Turn lists 20 damage. The cost is Water, Colorless. After your attack, you may switch Ditto with 1 of your Benched Pokémon. Weakness is Lightning ×2. Retreat cost is 1.
I keep a set binder for Delta Species, meant to hold every card of that set. This card is one slot in the Delta Species set binder. A generation binder holds one card of each species. Ditto can fill a slot in Generation 1 binder (Kanto). Themed lists that include this exact card are Yuka Morii clay cards. I still need this card.