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