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