Here is the full list of all 31 Idle Clans achievements.
Steal from the royal clan
Create a godlike item
Defeat a boss
Reach level 100 in a skill
The true test for any respectable chef... Make a pizza.
Join a minigame
Battle a monster with an Outstanding weapon
Grow some watermelons
Defeat a dragon
Receive a boss key
Enchant an item
Perform a leaderboard search
Send an item to your clan's vault
Eat a burger in battle
Create silver jewellery
Achieved upon reaching your first million
List an item for sale
Prepare a special dish
Purchase an upgrade
Refine an item
Plunder a small, helpless village
Equip diamond jewellery
Purchase your first property. It's nothing to brag to your parents about, but it's a start.
Your first level up
Join a clan
Create a clan
Complete the tutorial
Reach a billion gold
Reach max level in a skill
Smith a piece of Astronomical armour
Purchase the most glamorous property available