Dragon Quest II
The player can obtain an Yggdrasil Leaf by travelling south of the Sea Cave to an island with one tree on it. By searching this tree, the player can obtain the Leaf. The party can only get one leaf at a time from this tree and if the player already has an Yggdrasil leaf, they cannot get another one.
Dragon Quest III
The player can obtain a leaf by searching the centre point between four lone mountains northwest of Jipang. Similar to Dragon Quest II, only one leaf can be carried at a time by the player's party. Once used, the player can return to collect another.
Dragon Quest IV
Yggdrasil is a location in Dragon Quest IV. It appears simply as an immense tree hundreds of times the size of any real-world tree, with the elven village of El Forado at the base. Located slightly east of Mintos and surrounded by a ring of impenetrable mountains, it is only accessible by balloon flight.
The party visits it late in the game, after acquiring the balloon. After ascending to its boughs, they encounter Orifiela, a Zenithian who fell from the sky and landed in the Tree's branches. She helps them find the Zenithian sword, which is nearby, and, after being rescued, agrees to show them the way to Zenithia.
Dragon Quest VII
Yggdrasil can be found in Gröndal. When the party travels there in the past, Yggdrasil hasn't achieved maturity yet; it is a mere sapling known as Ygg. The residents of Gröndal, under the influence of a fighting batboon, try to cut down the sapling before it becomes Yggdrasil. The party stops this from happening and Ygg is able to become Yggdrasil. The party can obtain an Yggdrasil leaf by going to Yggdrasil. If the party does not have an Yggdrasil leaf, a bird will drop one from the tree for the party to pick up and obtain. If they do, the bird will not drop one. They can also obtain a phial of Yggdrasil dew at Gröndal. However, only the Hero can get on line to buy one and, if supplies run out before the Hero gets one, the party will have to leave town and enter again to try and get another one. If they already have one, they will not be allowed to buy another.
The Yggdrasil is considered the gateway to the realm of the Almighty, as when it blossoms the Starflight Express comes to ferry Celestrians. However, as part of the events of the game, when the tree blossoms, it instead causes a disaster in the Observatory.
The hero must venture down to the Protectorate to collect scattered Fyggs, which had fallen from the observatory in the disaster. It is later revealed that Yggdrasil is in fact the goddess Celestria, the daughter of the Almighty, Zenus. She became Yggdrasil to show Zenus that even though mortals were flawed, some still have good in their hearts.
The Luminary has a strong connection to the World Tree and can spiritually communicate with it through its roots around the world.
In ancient times, Yggdragon fought Calasmos, but was defeated and fell on a deserted Erdrea, later, he came back in force with the help of the lost time spirits and took the form of Yggdrasil, making Erdrea flourishing, later he generated Erdwin in order to defeat Calasmos, but since he did not succeed, he later generated the hero, who finally defeated the dark one and was named "Erdrick" by Yggdragon.
The World Tree is located in the kingdom of Arba.
Joker 2: Professional
The Yggdrasil is a monster made by synthesizing Watabou (alias Fluffy) and Warubou.
Dragon Quest Builders
Yggdrasil behind the Green Teleportal in the Rimuldar area, but due to the Dragonlord's attacks on it was reduced to withered stump. It's where the legendary Builder learns how to make the Transmutation Table.
Yggdrasil comes from Norse mythology. It literally means World Tree and it is the metaphorical "back bone" that supports the nine realms of the universe upon its branches.