The Stone Slammer can still be used if there are no Clan Castle troops, however, when it is destroyed, nothing will spawn from it.
The Stone Slammer can be described as an incredibly high hitpoint, high damaging Balloon, as it shares the Balloon's relatively slow movement speed and high DPS with low attack speed, as well as defense targeting. However, the Stone Slammer has considerably more DPS.
The Stone Slammer's attack consists of two parts that act simultaneously: one high-damage hitbox with low splash radius (1 tile) that usually only affects the building it's attacking, and a low-damage hitbox with high splash radius (3 tiles) that does 25x damage to Walls. The low-damage hitbox has a falloff effect that does less damage when between 2-3 tiles away from the Stone Slammer. Additionally, the Stone Slammer does some damage when destroyed.
As the two hitboxes overlap, the targeted building that gets hit by the first hitbox will get hit by the second hitbox as well, meaning the Slammer effectively deals more damage than that done by the first hitbox alone.
Stone slammers have one noticeable difference from the rest of the siege machines: They will not kill themselves when they reach the Town Hall!
This is very useful! One of the best companion armies for this siege machine is the "lavaloon" strategy, for it will hide behind the hounds and do big hits of damage.
Also, the wall destruction makes a clear path for a queen walk, which has the potential to do heaps of clean up, for she will target the buildings the Slammer and Balloons won't.
The biggest threat to this siege machine is the single target Inferno Tower, so it is wise to haste spell the balloons, therefore they will reach the range of the Inferno Towers before it does.
Guard your Inferno Towers ( and set them to Single Target mode ) with Wizard Towers, so they can take out lots of balloons at once, this will allow the Inferno Towers to do maximum damage to the Slammer.
Initially, the Stone Slammer is a balloon-like, roped machine with wooden supports and nails reinforcing the bottom.
At level 2, The nails become gold and the wooden reinforcement pieces are plated with metal inserts.
At level 3, the top junction of ropes gleans golden plates, while the metal inserts become gold.
*This second hitbox does its maximum damage for all targets within 2 tiles of the impact, and minimum damage for targets just within the splash zone of 3 tiles. The hitbox also does x25 damage to Walls.