The Windy -- Episode 1 -- Owned by Sakura Kinomoto --
The card that started it all. By reading the card, Sakura scattered all the Clow Cards, and awoke Cerberus. Windy, as it's name suggests, is a card that creates a gust of wind.
Used to - Make a powerful wind that will throw opponents off guard.
Kero-chan says - "Windy is a high level card but gentle.."
The Fly -- Episode 1 -- Owned by Sakura Kinomoto -- This card was the first card ever captured by Sakura. In it's out-of-card form, it appears as a large bird. Sakura used the Windy to capture this card, seeing as it was the only card she had at the moment. Naturally, it allows one to fly. (What were you thinking it would be? A giant fly? o.O;;) Sakura uses it to sprout wings on the Clow key, so she can fly.
Used to - Escape and dodge enemies
Kero-chan says - .. Nothing.. o.O;;
The Shadow -- Episode 2 -- Owned by Sakura Kinomoto --
The Shadow card's form is...well think of a Christmas Carol's the Angel of Death. Shadow, was captured with Windy, after Sakura found the main card. It usually does mischevious things like piling up all the students' desks, or moving objects around. Used to - Confine enemies, and manipulate objects, as if the shadow were a physical body.
Kero-chan says - "Shadow uses people's shadows, but will dissapear with light, leaving only the main card."
Costume - Tomoyo showed Sakura and Kero-chan a truckload of costumes with matching hats and shoes. Approprietly enough, Kero-chan got a costume too. Red bow, with a gold medallion.
Themed - Bats and Bows
The Watery -- Episode 3 -- Owned by Sakura Kinomoto --
The Watery is a higher level card with a violent temper. It's formless, and is usually in water, appearing as a whirlpool. When out of water, it appears as a wave. Sakura captured Watery with Windy, after trapping it in a freezer.
Used to - over power opponents with a large surge of water
Kero-chan says - "Watery is not visible in water, and even if you do pull it out, it scatters, and is hard to deal with. It's hard to catch something that is formless, and has a violent temper."
Costume - Blue Jester frill with bells
Themed - Court Jester

The Wood & The Rain -- Episode 4 -- Owned by Sakura Kinomoto Sakura found both of these cards in their card form, while cleaning up the house. But when left unattended, they grew into their out of card forms. Apparently, the card will only obey Sakura, if her name is written on them. Sakura caught the Rain with Watery, but the Wood kind of allowed itself to be caught. The Rain is a more mischevious and playful card, and appears as a small girl riding on a rain cloud. The Wood began to spread all throughout Sakura's house searching for daylight, so it's leaves could bloom, and looks like a young woman covered in branches and leaves.
Used to - cover opponent in a rain fall, and create a forest
Kero-chan says - "The Wood is a good-tempered card, and wouldn't do anything harmful. However, Rain and Wood effected eachither, and created a jungle"
Costume - None
Themed - Uhh.. Sakura's costume looks like all the parts are made of balloons