From Nookipedia, the Animal Crossing wiki
Wendell (セイイチ, Seiichi) is a wallpaper salesman and traveling artist in the Animal Crossing series. He has slightly different roles in each game appearance, but they all revolve around his artistic ability and design skills. He is a blue walrus with two large, white tusks. He wears a t-shirt which does not cover his large, round stomach, which has a small cross for a belly button. He always carries canvas and a traveler's backpack with him.
In Animal Forest, Wendell has a role that is basically the same from Animal Crossing. The only difference is that he only eats fish.
Wendell has a wallpaper selling role in Animal Crossing. He will show up in the player's town on Saturday or Sunday, but has been known to show up on other days, too. He appears at a random time of day. He will tell the player he is hungry upon talking to him, and will ask for food. He will eat anything, including fruit, fish, and turnips. He will give some wallpaper to the player for free as a reward during the weekend and will sell it to the player during weekdays. He disappears after a while.
Wendell's role in Wild World is different than it is in Animal Crossing. This time, he gives out unique designs. Upon giving him something to eat when he visits the town, he gives a pattern that is unobtainable anywhere else. He will eat fruit and turnips as well as fish. His extreme hunger may be a reference to the stereotypical phrase "starving artist," as he is both. Giving him any type of fruit will yield a pattern already obtained, with the exception of coconuts, which yield a different pattern. He does not appear on Sunday or Saturday anymore. Instead, he appears from 6 A.M. to midnight on a random weekday (excluding the day Redd comes). In Wild World, Wendell comes from Tuskany. When one of his designs is displayed at Able Sisters, it will say Wendell from Tuskany. Tuskany is a pun involving the town Tuscany, Italy and tusks, which are a predominant feature on walruses. Wendell is the first step in the Golden Axe Trading Event.
A full list of his designs in Wild World can be found here.
Wendell has the same role in City Folk as he did in Wild World, excluding the Golden Axe Trade Event and Redd (who now has a store in the City). If the player puts Wendell's designs on display at Able Sisters and ask to receive one of them, Mabel says, "That design is made by Wendell from Sumware", his town name which is a pun on "somewhere."
A full list of his designs in City Folk can be found here.
In Animal Crossing: New Leaf, Wendell appears in Dream Towns distributing the custom designs from the town residents. His appearance is changed; he now wears a nightcap and pajamas. Owners of the town can choose not to let him appear, if they wish.
Wendell briefly appears in the movie, seen eating with Ai.
Animal Crossing e-Reader card
Happy Home Designer amiibo card
Wendell appears as a trophy and can be seen in the Smashville stage.
As mentioned before, Wendell appears as a trophy and can be seen in the Smashville stage. He now also appears in the Town and City stage.
Names in other languages