Here is the full list of all 31 Idle Clans achievements.
Join a minigame
Grow some watermelons
Achieved upon reaching your first million
Receive a boss key
Eat a burger in battle
Enchant an item
Defeat a dragon
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
List an item for sale
Perform a leaderboard search
Purchase an upgrade
Send an item to your clan's vault
Join a clan
Create a clan
Plunder a small, helpless village
Your first level up
Complete the tutorial
Reach a billion gold
Reach level 100 in a skill
Reach max level in a skill
Defeat a boss
Steal from the royal clan
The true test for any respectable chef... Make a pizza.
Create a godlike item
Battle a monster with an Outstanding weapon
Equip diamond jewellery
Smith a piece of Astronomical armour
Purchase the most glamorous property available