Here is a page showing the following wallpapers that Zynga has made for the Computer and Iphone/android. Fanmade wallpapers can be found at the last section.
Behemoth (Calm) Wallpaper
Behemoth (Calm) (Tanabata) Wallpaper
Waterfall Spirit Wallpaper
Bisque Doll (Tanabata) Wallpaper
March Hare [Tanabata] Wallpaper
Kotetsu [Focused] Wallpaper 1
Kotetsu [Focused] Wallpaper 2
Ōtomo no Yakamochi Wallpaper
The Princess [Halloween] Wallpaper
Shotaro Fuma (Tanabata) Wallpaper
Bisque Doll [Halloween] Wallpaper
Jack-O-Lantern [Revival] Wallpaper
Walpurgis Night Wallpaper
Kenshin Uesugi [Summer] Wallpaper
Pumpkin King [Wild] Wallpaper
Satori (Tanabata) Wallpaper
Scorpio [Fallen] Wallpaper
Shuten-doji (Calm) (Tanabata) Wallpaper
Ameno Uzume [Focused] Wallpaper 1
Ameno Uzume [Focused] Wallpaper 2
Alice [Shichi-Go-San] Wallpaper
Shangxiang Sun [Shichi-Go-San] Wallpaper
Sagittarius [Fallen] Wallpaper
Tendo Hidari-uma Wallpaper
Dojigiri [Mt. Fuji] Wallpaper
Kin Byobu [New Year] Wallpaper
Pipe Fox [Focused] Wallpaper
Capricorn [Fallen] Wallpaper
Ame no Habakiri Wallpaper
Aquarius [Fallen] Wallpaper
Ikutachi the Living Blade [Winter Style] Wallpaper
Sanuki no Miyatsuko [Princess Wars]
Ninomiya Sontoku Wallpaper
Charismo Chris [Academy] Wallpaper
Pisces [Fallen] Wallpaper
Mordred [Academy] Wallpaper
Guinevere [Academy] Wallpaper
Merlin [Academy] Wallpaper
Amenonuhoko [Academy] Wallpaper
Thousand Sakura Wallpaper
Yamataka Jindai Sakura Wallapaper
Sakura Sumizome Wallpaper
Maeda Toshimasu [Circus] Wallpaper
Cat Sith [Circus] Wallpaper
Il Milione [Circus] Wallpaper
Taurus [Fallen] Wallpaper
Amaymon [Anniversary] Wallpaper
Lady Wedge [Anniversary] Wallpaper
Lunar Hare [Anniversary] Wallpaper
Shuten Doji [Anniversary] Wallpaper
Shangxiang Sun [Anniversary] Wallpaper
Mira [Anniversary] Wallpaper
Gemini [Fallen] Wallpaper
Hades [AYA Cup] Wallpaper
Demon Motochika [AYA Cup] Wallpaper
Hashihime [AYA Cup] Wallpaper
Cancer [Fallen] Wallpaper
Shield of Achilles Wallpaper
No. 3 Toilet Stall Wallpaper
Orihime [Yggdrasil] and Hikoboshi [Yggdrasil] Wallpaper
Orihime and Hikoboshi Wallpaper
Orihime [Yggdrasil] Wallpaper
Moon Viewing Pickpocket Wallpaper
Gamesmaster Gloria Wallpaper
Red Riding Hood [Werewolf] Wallpaper
Werewolf [Wild] Wallpaper
Momotaro [Werewolf] Wallpaper
Titania [Werewolf] Wallpaper
Satori [Werewolf] Wallpaper
Vanilla [Werewolf] Wallpaper
Juliet [Werewolf] Wallpaper
Magician [Reversed] Wallpaper
Valkyrie Ono no Komachi [Medieval] Wallpaper
Alchemist Kashinkoji [Medieval] Wallpaper
King's Vestments Wallpaper
Troubadour Garland Wallpaper
Koi Carp [Medieval] Wallpaper
Omatsu [Medieval] Wallpaper
Tsukuyomi [Medieval] Wallpaper
Competitive Strange Wallpaper
High Priestess [Reversed] Wallpaper
Murata the Hunting Gun Wallpaper
Pumpkin Pie [HW3] Wallpaper
Jack-O-Lantern [HW3] Wallpaper
Confectionery Queen [HW3] Wallpaper
Trick or Treat [HW3] Wallpaper
Murasaki Shikibu [HW3] Wallpaper
Walpurgis Night [HW3] Wallpaper
Cook Nyamaoka [HW3] Wallpaper
Halloween Tower [HW3] Wallpaper
The Maiden Queen [HW3] Wallpaper
Empress [Reversed] Wallpaper
The Tree of Wisdom Wallpaper
Fairy Godmother Wallpaper
Utagawa Kuniyoshi [Amusement Park] Wallpaper
Dojigiri [Amusement Park] Wallpaper
Athena [Amusement Park] Wallpaper
Lord of the Stars Wallpaper
Sleeping Beauty Wallpaper
Ibaraki Doji [Amusement Park] Wallpaper
Amakusa Shiro [Amusement Park] Wallpaper
Planetarium [Amusement Park] Wallpaper
Ryoma Sakamoto [Ronin] Wallpaper
Ryoma Sakamoto [IF] Wallpaper
Rhongomiant [Xmas Eve] Wallpaper
Holly the Reindeer [Xmas Eve] Wallpaper
Pipe Fox [Xmas Eve] Wallpaper
Cu Sith [Xmas Eve] Wallpaper
March Hare [Xmas Eve] Wallpaper
Hare of Inaba [Xmas Eve] Wallpaper
Queen of Swords Wallpaper
Hierophant [Reversed] Wallpaper
Ameno Uzume [Snow] Wallpaper
Cheshire Cat [Fashion Show] Wallpaper
Isolde [Fashion Show] Wallpaper
Yeti [Fashion Show] Wallpaper
Bisque Doll [Fashion Show] Wallpaper
First Dream of the Year Wallpaper
Prince of Pentacles Wallpaper
Chiyome Mochizuki Wallpaper
Princess Konohanasakuya Wallpaper
Kakinomoto no Hitomaro Wallpaper
Behemoth (Calm) [Xmas] Wallpaper
Nagamitsu Daihannya Wallpaper
March Hare (Tanabata) Wallpaper
Behemoth (Calm) (Tanabata) Wallpaper
Orihime & Hikoboshi Wallpaper
Orihime & Hikoboshi [Yggdrasil] Wallpaper
Satori (Tanabata) Wallpaper
Shuten-doji (Calm) (Tanabata) Wallpaper
The Princess [Summer] Wallpaper
Kenshin Uesugi [Summer] Wallpaper
Emperor Wulie [Summer] Wallpaper
Hansel [Summer] & Gretel [Summer] Wallpaper
Bisque Doll (Tanabata) Wallpaper
Satellite Cannon Wallpaper
Galaxy Wars: Purity Wallpaper
Walpurgis Night Wallpaper
Amaterasu [In Hiding] Wallpaper
Pipe Fox [Focused] Wallpaper 1
Pipe Fox [Focused] Wallpaper 2
Lunar Hare (Eggplant) Wallpaper
Udaijin [New Year's Eve] Wallpaper
Top 10 Dojigiri Wallpaper
Top 8 Ameno Uzume Wallpaper
Top 6 Princess Konohanasakuya Wallpaper
Top 2 Shuten-doji Wallpaper
Top 1 Amaterasu Wallpaper
Waterfall Spirit Wallpaper
Ame no Habakiri Wallpaper
Moon Viewing Set [Hot Springs] Wallpaper
Bunchu [Chinese New Year] Wallpaper
The Great Princess Wars Wallpaper
Odairi & Ohina [Princess Wars] Wallpaper
Camelot Academy for Ghosts Returning Daemons Wallpaper
Sengoku Celebration Wallpaper
Garden in Full Bloom Wallpaper
Mira [Anniversary] Wallpaper
Shuten-doji and Ibaraki-doji
Barbatos and Ikutachi the Living Blade
Shotaro Fuma (Tanabata) Wallpaper
Kotetsu [Xmas Eve] Wallpaper