He appears as a colossal skeleton holding a large explosive, which, upon his death, is 'carelessly' dropped, dealing an enormous amount of damage to all enemy troops/buildings surrounding it.
The bomb explodes 3 seconds after it is dropped.
The Giant Skeleton is effective to use as a meat shield for other troops. This makes it a good card to use as a buffer for spawner buildings, as any card that takes out the Giant Skeleton will be taken out by its bomb afterwards while the spawner cooks up troops. They will continue unopposed to the Crown Tower. However, it is not very interchangeable with a Giant, as the Giant Skeleton will attack any troop, not only buildings.
It is excellent for taking out large swarms of troops due to its death damage, completely wrecking pushes. The Giant Skeleton is very effective as a distraction card, as most cards that your opponent deploys to counter it (i.e. Barbarians, Musketeer, Valkyrie) will be taken out by the death damage for a positive elixir trade if more than one card is on the battlefield.
Fast troops like the Hog Rider can avoid the bomb before it blows.
Troops that survive the bomb and are affected by pushback will quickly be launched towards their next target, providing a type of "quickstrike" to compensate for the immense damage taken. For example, a Valkyrie that survives the bomb will quickly be pushed towards her next target, although she will probably only get one hit off.
If you are stopping a push with fast troops such as Lumberjack and Elite Barbarians, you can use the Tornado spell to pull them and any other support troops to the bomb.
The Giant Skeleton is also useful for taking out Crown Towers, as when the bomb explodes upon the Giant Skeleton's death, it will deal a lot of damage to the Tower.
Using Clone when the Giant Skeleton reaches the tower will double the Death Damage.
This can also be good for defense, as it will stop all troops but tanks now.
It is imperative to eliminate troops that may attack the Giant Skeleton so that it can get the giant bomb to the enemy Crown Tower and deal immense damage.
The Giant Skeleton can be punishing to large amounts of weak troops because of its bomb. The Inferno Tower is an effective counter, as it can easily take down a Giant Skeleton without a large group of troops, and unnecessary usage of Elixir.
Even though the Giant Skeleton's bomb can do high damage against the opposition's tower, often the best uses for the Giant Skeleton lie on defense. The player can place him in between troops (just like how they would place a Valkyrie), the death damage bomb taking out the support troops, allowing the player to deal with the survivors separately.
Due to the numerous ways to dispose of the Giant Skeleton, it is unwise to send him alone unless the player knows for sure that the opponent is low on Elixir, or does not have an appropriate counter to the Giant Skeleton.
The Giant Skeleton is perhaps the best counter to Sparky combos, i.e Sparky + Wizard. The ideal time and place to put him are after the two cross the bridge. Place the Giant Skeleton in between the two troops. It is crucial here that he hits the Sparky so that his bomb can fully destroy the Sparky and the Wizard.
A strategy for the Giant Skeleton to reach the opponent's Crown Towers is to place it first, then placing a Hog Rider behind it. Because the Hog Rider targets buildings, he will push the Giant Skeleton very quickly towards the Crown Tower, allowing the Hog Rider to get free hits while the Giant Skeleton survives and absorbs damage.
The player can devastate an enemy's Crown Tower by placing the Giant Skeleton with the Balloon so that the opponent is forced into trying to distract and kill both of them.
However, Minion Horde would destroy the combo, probably only taking one Balloon hit and death damage.
This is why if you use it, you must use Witch/Wizard and Arrows to take the Minion Horde.
If the player has taken out a Crown Tower, then the option appears to place the Giant Skeleton on the opponent's side of the arena. He will march straight towards the other tower quickly, and if the opponent has been ignoring the Giant Skeleton or has lost a tower because of him, the player should use this to their advantage and plunder their opponent.
Giant Skeletons are well countered by swarms of troops like Barbarians, Minions, and the Minion Horde, or troops with good hitpoints and damage like the Knight or Mini P.E.K.K.A. However, Barbarians must always be placed behind the Giant Skeleton so that they have enough time to run away before being blown up. Minions can usually run away before the bomb blows up either way.
A reliable if not very efficient way of countering (or at least delaying) a Giant Skeleton is to drop a Giant in front of the Crown Tower. The Giant will ignore the Giant Skeleton's meager damage per second and trundle onward, pushing the Giant Skeleton (and more importantly, its bomb) away from the Crown Tower.
Putting a Dark Prince behind the Giant Skeleton has many benefits as the Dark Prince pushes the Giant Skeleton with its speed, kills any swarms trying to kill the skeleton, and it has a shield so when the Giant Skeleton dies, the Dark Prince along with the enemy troops will stay near the bomb.
When the Giant Skeleton is targeted by the tower, the player can place a Miner at the back of the tower so that they will have to choose to deal with either one.
If a Mini P.E.K.K.A. is placed behind a Giant Skeleton it will not only push it towards the tower but also deal heavy damage to the tower. The Giant Skeleton can blow up the tower and act as a tank while the Mini P.E.K.K.A. destroys. However, it is very weak to swarms so bring a spell.
If the player wants to make sure their Giant Skeleton reaches the Crown Tower with enough elixir to provide a counter for any cards the enemy deploys, they must make sure to place the Giant Skeleton behind the King's Tower. As the Giant Skeleton marches on with its relatively slow speed, they will build up enough elixir to either deploy a spell or splash damage card before it crosses the bridge. Either a Wizard/Witch or Bomber is best, as they are ranged and deal high damage; on the contrary, the Valkyrie and Baby Dragon are melee and have low damage per second respectively.
This strategy can still easily be countered by using either a Valkyrie if the card dropped as support is a Bomber or a Wizard, as the player can wait until the Giant Skeleton is across the bridge, and then deploy the Valkyrie between them. The Giant Skeleton will be damaged by both the Valkyrie and the Crown Tower, and its support will quickly be destroyed by the Valkyrie's splash damage. On the other hand, if the support card is only able to target ground troops, the player should use Minions or Minion Horde. However, if the opponent who dropped the Giant Skeleton has not deployed any cards thereafter, they most likely are waiting for the player to drop their cards so they can use a spell to take out the cards.
If the player is trying to rush the Giant Skeleton to the Crown Tower, Fire Spirits are recommended, as any swarm that will counter the Giant Skeleton can be devastated or even destroyed. (They should place them on the road with the Giant Skeleton in the front and use Fire Spirit as a boost.) However, a mini-tank, like Ice Golem and then the Skeleton Army will make short work of this combo.
The Giant Skeleton is useful when placed in front of a Wizard to prevent the Giant Skeleton from getting destroyed by the Skeleton Army or other swarms. After the Wizard dies, place your Skeleton Army to counter the Prince or the P.E.K.K.A. When the Giant Skeleton dies. Carry on with this strategy but don't forget to place other troops. The Zap might destroy the army, so be careful with placement!
The Giant Skeleton was added with Clash Royale's soft launch on 4/1/16.
On 2/2/16, the February 2016 Update added the Death Damage on the Giant Skeleton's card info screen.
On 29/2/16, the March 2016 Update increased the Giant Skeleton's hitpoints by 11% and bomb timer to 3 sec (from 1 sec).