The spy. It takes the form of one of your pawns but only you know which pawn is the spy.
If the spy kills a piece the way a regular pawn does, it ceases being a spy and reverts to bring a regular pawn.
If you position the spy on one side of an enemy piece with another of your pawns on the other side of it, you can recruit the piece as a pawn on your side (regardless of what class it was)
Kings and Queens are immune to spies.
When a spy is killed, any pieces it recruited are reverted to enemy pawns.
My new car is a 2025 model, but it's an Indian made Japanese Kei car so the interior is super basic. and it has large, infinitely spinning knobs for temperature and fan strength, and a digital temperature readout. I really like them.
When the temp was cold in the morning but now it's hot, I spin those dials like wheel of fortune to the left and immediately set the AC to cold and fast. No repeated button presses.
The only downside is that it doesn't have one of those knobs for music volume.
Perfection 👌