From Nookipedia, the Animal Crossing wiki
Katrina (ハッケミィ, Hakkemii) is a blue female panther, with dark purple eye makeup and bright orange eyes. She can tell the player their fortune, and appears in all Animal Crossing games. In Animal Crossing she has a male voice like Gracie and Saharah (who are both male in Japan), but in Animal Crossing: Wild World and Animal Crossing: City Folk she has a female voice.
 In Animal Forest
 In Animal Crossing
In the original Animal Crossing, Katrina's tent will appear randomly in location and by date. She can tell the player their fortune for 50 Bells using her crystal ball. Copper can let the player know when she will appear in their town a few days in advance. Her tent is open from 9:00 P.M. to 9:00 P.M. the next day. On New Year's Day, she will set up a desk by the Wishing Well, giving the player a letter with a fortune in it. The effects of the fortune last the rest of the day.
Katrina's role in Wild World is generally the same as in the original Animal Crossing, however, Katrina uses cards to read the player's fortune rather than a crystal ball. Katrina's tent will appear randomly in front of the Town Hall on a random weekday. She can tell the player their fortune for 100 Bells. Additionally, she can tell players how compatible they are with someone else for 100 Bells or cleanse their spirit (which clears the effects of bad luck) for 10,000 bells.
In City Folk, Katrina can be found in the city in the building furthest to the right, telling fortunes or lucky charms for 100 bells. She will greet the player by the player's star sign (e.g. if the player's birthday is on March 15th, she will call the player a Pisces). She can tell the player their fortune once a week, and/or she can give the player a charm for that month, usually involving strange tasks. However, the player who is given the fortune cannot obtain the charm - the task stated by Katrina needs to be done by a visiting player and only they may obtain the charm. One would have to cooperate with a friend to do the prescribed tasks in each other's towns to obtain the charm. No matter what the player asks her to do, she will have something drop on their head. It will make the player wobble and be "dizzy" (stars appear around the character's head). It should be noted that Katrina uses her crystal ball in this game, like in Animal Crossing.
In Animal Crossing: New Leaf, Katrina visits the player's town on random weekdays and will tell the player's fortune for 500 bells. Once the player has had their fortune told twenty times, the Fortune Shop on Main Street will become available as a public works project, which requires 340,000 bells to complete.
 Other appearances
The below fortunes are the responses given by Katrina to the player. These are also followed by the effects.
 City Folk
 New Leaf
 Names in other languages