Rukh

Rukh is a Pre-Hardmode Boss that is summoned in the desert.

(It is summoned using the Desert Crown.)

You can travel to a different biome and it won't leave, neither will it enter an "Enraged" mode.

Rukh's attacks usually do a base damage of 20 which is very dangerous for new players if encountering Rukh.

The boss has 2500 health in normal mode.

(I will update this saying the Expert Mode health and drops so don't panic.)

Now, the weapon recommendations.

I would pick the Water Bolt because it pierces multiple enemies and an attack where he summons a horde of Vultures is very easy to beat if you use a Water Bolt.

Another weapon suggestion is the Krore, a Yoyo that inflicts a bunch of debuffs like Ichor, Cursed Flames and Frostburn.

All of which Rukh is not immune to.

However, after defeating Rukh, it will say 'A RUKH DOPPELGANGER HAS BEEN DEFEATED!'

You must defeat the second phase, the Sunlight Trader Big Bird.

After defeating Big Bird, you must download Terraria 1.1.2 to fight his 3rd phase, Desert Beak

This is one of the hardest phases, since you have less inventory slots and Desert Beak has connections with terrorist groups, thus he has many explosives.

Then, you must defeat his 4th phase, Steelfang, in hardmode, summoned using /summon. He has 100 original AI. After beating him, you can get your reward: The Bronze Shortsword