The Warden is a hostile mob that will be appearing in the 1.17 Caves and Cliffs update.
The Warden will become the first blind mob in Minecraft. Instead of following the player as usual, the Warden uses the sculk-like sensors at its head to detect vibrations.
To avoid fighting the Warden, you can sneak or throw projectiles like snowballs or even arrows to distract the Warden. This was demonstrated during the Minecraft Live 2020 event. The reveal revealed that Wardens will be attracted by projectiles that make a sound. Fighting the Warden is not a good idea, as it can cause a lot of harm. Mojang developers stated that the Warden is not to be defeated, but is there to scare players. People on some Minecraft servers are already clamoring to get a piece of him.
The Warden appears to be faster when it is attacked and can kill a player with full netherite armour in just two hits. Any weaker armor, or no armor, will result in the player getting killed in one hit.
If the player sneaks past the Warden, the Warden will not hear them. However, if they attack it enough, the Warden will keep its attention on them and not be distracted by any other sounds. It will now charge at the player much faster than it did before.
The warden will attack any player who attempts to get near it, or attempts to use poison, wither or other similar status effects on it.
Its heartbeat can be heard as well as seen. The more it is attacked the stronger it becomes, and the more soul-filled it becomes, the brighter its heart glows.
If you're looking to play Minecraft you can check out a server list to get a head start at preparing to face the warden.