Dragonvale is a park sim along the lines of FarmVille available on iOS devices. The player runs a zoo/conservatory for dragons, and they must purchase elemental habitats and dragon eggs, as well as breeding new species of dragon. Dragons collect coins based on their type and level, and levels are increased with dragon snacks (which in turn cost coins).Now has its own trivia page!
This game provides examples of:
All Your Elements Combined: The Panlong Dragon has all four classical elements (Fire, Water, Earth, Air) at once and the Paper Dragon (released on DragonVale's first anniversary) has the first four elements from the game (Plant, Fire, Earth, and Ice).
Breath Weapon: Most dragons have their own elemental breath. This ranges from ordinary (fire breath for fire dragons, ice breath for ice dragons, etc.) to unusual (Gold Dragons breathe gold coins, Rainbow Dragons breathe rainbow sparkles). Two-headed dragons, like the Brass and Solstice dragons, each have different breaths. It is mostly for show, of course.
Bribing Your Way to Victory: Food, coins, and the rare crystals are all available for purchase for real money. Getting them, especially the crystals, makes the game far, far easier.
Cherry Blossoms: The Sakura Dragon was released in late April, to correspond with sakura-zensen. It was available until early May.
Color-Coded Elements: Each element has its own color: green for Plant, red for Fire, brown for Earth, light blue for Cold, yellow for Lightning, blue for Water, purple for Air, orange for Metal, light yellow/white for Light, and dark purple/black for Dark. All of the basic element dragons come in these colors, save for the Air Dragon, which is dark blue and cyan. This also allows players to identify what kind of egg they have. The primary color scheme of hybrid dragon eggs corresponds with its main element and the pattern on the egg corresponds with its secondary element. For example: Lava, a Fire/Earth hybrid has a red egg decorated with small stone chips.
Elemental Rock-Paper-Scissors: Most elements have a opposite, which they cannot be bred with (fire and cold, or earth and air, for example), unless you create a hybrid first. They will also be affected negatively by the Boost item for their opposite element.
Infinity+1 Element: Originally Rainbow, Sun, and Moon; which had their own habitats and couldn't be bred with dragons of other types. Treasure, Olympus, Seasonal, and Apocalypse Dragons were later added to this level; but by then they had been surpassed by Gemstone Dragons, which have their own island, can't be bred period, and generate crystals instead of coins.
Everything's Deader with Zombies: The Zombie Dragon was the third Halloween-themed dragon to be added to the game. Its description makes a reference to the popularity of this trope. It's also mentioned to not necessarily eat other dragons... as long as it's properly fed.
Experience Points: Most actions, from feeding your dragons to clearing away dead trees, will net you experience.
Floating Continent: Your zoo is located on a floating island. As you level up, you can get a whole archipelago of islands for your zoo plus the crystal-only epic breeding island.
Follow the Leader: Of FarmVille, which was itself following other Facebook games. It was later followed by other dragon-breeding apps like Dragon Story.
Fountain of Youth: An actual fountain which allows your mature dragons to revert to their baby stages while retaining their levels. The effects can also be reversed.
G-Rated Sex: Breeding Cave descriptions admit that nobody's sure exactly how breeding happens.
Doubles as Fridge Brilliance: Saying the breeding is just 'magic' and nobody's sure how it happens can help avoid awkward questions when you have kids playing the game.
Gold Makes Everything Shiny: The Gold dragon, one of the rarest dragons to breed in the game, which also needs its own special habitat (now shared with a few others now). Also the most expensive pathway in the game is gold, which costs a whopping 7500 gold pieces per tile.
Gold Silver Copper Standard: The Treasure Dragons, which have their own habitat, though this standard is Platinum/Gold/Silver/Bronze. There is a Copper Dragon, but it is a lightning and metal hybrid.
Also, there are three tiers of Olympus Dragons: Bronze, Silver, and Gold to correspond with their Olympic theme.
Gotta Catch 'Em All: All the different breeds of dragons, including rare dragons and holiday-only dragons. There's even an achievement for it, though some of the rare ones aren't strictly necessary to get it.
Holiday Mode: The islands change with the seasons, being snowy in winter and green in summer. There are also season-themed decorations for the islands and holiday-only dragons which can only be bred in the month surrounding their respective holidays.
In fact, exaggerated, considering the list of holidays and events that get their own dragons include the Chinese Year of the Dragon (the Panlong Dragon), the leap year, Valentine's Day, St. Patrick's Day, April Fool's, Earth Day and Arbor Day, the Japanese Cherry Blossom festival (the Sakura Dragon), Mardi Gras, Mother's Day and Father's Day, Deaf Awareness Month (the Butterfly Dragon), the solstice, the equinox, 4th of July and Bastille Day, the Summer and Winter Olympic Games (the Olympus Dragons), the blue moon, and the 2012 end of the Mayan calendar (the Apocalypse Dragon). Plus each month gets its own Gemstone Dragon, based on that month's birthstone.
Hybrid Overkill Avoidance: There are many crossbreed dragons, but when hybrid dragons breed their offspring will usually have two of their parents' types; no more. Though there are a couple of exceptions when it comes to holiday-only dragons (the Panlong Dragon has the four classical elements; the Love Dragon is fire, lightning, and plant). The Rainbow Dragon is also implied to have all eight types at once.
Each of the Gemstone dragons can only be bred by a unique combination of hybrid dragons.
In-Universe Game Clock: Everything in the game runs on real time. Dragons earn coins per minute, food crops take between 30 seconds and one day, depending on amounts, breeding dragons takes hours, as does hatching eggs and constructing habitats. There are also a lot of dragons based on the calendar and related astrological events (the leap year, the solstice and equinox, the blue moon...).
Last Lousy Point: The Leap Year and Blue Moon Dragons. They're not required for any achievements or anything, but most holiday dragons are only available for a few weeks a year. These dragons are instead only available for a matter of days, and only show up every three or four years. (That said, the game has had at least one event where for a month or two every dragon was made available.)
Palette Swap: The Blue Fire, Frostfire, Malachite, Plasma, Current, Leap Year, Sandstorm, and Ironwood dragons are recolors of the Fire, Cold, Metal, Lightning, Water, Rainbow, Air, and Plant dragons, respectively. The Dodo dragon has the same body as the Earth dragon, but has horns on its head and wing-like feathers on its back rather than spikes.
Head Swap: The Clover dragon, which has the Flower Dragon's wings and body with minor alterations, but an original head and tail tip. The Solstice dragon is a two-headed version of the Sun dragon and the Blue Moon dragon has a horn on its head and a full moon on its tail rather than a crescent moon.
Petal Power: The Flower, Bloom, Sakura, Rose, and Bouquet Dragons.
The Power of the Sun: The Sun Dragon. The Solstice Dragon is a two-headed variant which was released around the summer solstice for two weeks. Its breeding time is 23.5 hours, the number of degrees the Earth is tilted on its axis.
The Metal dragon's description states that it was found in the Tull Caverns by an explorer named DickinsonOsbourne.
The description for the Large Plant habitat has references that are legend—wait for it— dary!.
The Love Dragon's description references a mountain range named the Berrywhite mountains.
Everything about the Zombie Dragon seems to be a reference to zombie tropes.
Spiritual Successor: Gizmonauts by the same creators, which in many ways just exchanges dragons for robots.
Time Master: Kairos, the first legendary dragon of the game, can accelerate any event in the game by a few hours (breeding, building, etc.)
A Wizard Did It: Quite literally the explanation for everything from why you can have frozen patches of ground for your cold dragons to how your islands are constructed and summoned.
Wings Do Nothing: When the Lava Dragon grows, its wings don't, yet it's still capable of flying. This led to the conclusion that Lava Dragons use magic to fly. The Iceberg Dragon also has wings that are too small for its large body.