Terraria – What equipment should I have to kill the Eye of Cthulhu

It is possible to spawn the Eye of Cthulhu by using a Suspicious Looking Eye.

This item needs to be crafted from 6 lenses. Lenses are occasionally dropped by Demon Eyes (the flying eyes that attack at night along with zombies).

Once you have collected 6 lenses you will need to find a Demon Altar in order to craft the Suspicious Looking Eye. You will probably have to do a bit of searching underground in order to find one of these if you haven't already found one.

Note that in order to summon the Eye of Cthulhu it must be night time. If dawn breaks while fighting the Eye, it will fly away to return the next night with full health.

Bear in mind that the Pumpkin Moon and Frost Moon events are considered end-game - they are supposed to be difficult for very well geared players. If you're not a very well geared player, don't expect to get to wave 15. Also, I'm not going to list any items that drop from the Pumpkin Moon or Frost Moon events - if you were able to get those items then you likely don't need to be reading this answer in the first place.

_{Note: all links are to the official Terraria Wiki unless stated otherwise.}

In terms of gear, you may want to consider investing some time aquiring the following:

Weapons

• Vampire Knives. Multi-shot, lifestealing, very fast speed, reasonable damage. Only obtainable from worlds naturally containing Crimson biomes. Does melee damage.
• Golden Shower. Piercing damage (up to 5 enemies), inflicts the Ichor Debuff which reduces enemy defence by 20 for 10 seconds. Relatively cheap to cast, makes your Vampire Knives do more damage = more healing. Again, you'll need a Crimson world to get the ingredients to craft this.
• Scourge of the Corruptor. No mana cost, high damage, fast attack speed and homing projectiles. Not as useful in later waves due to the lack of self-healing, but is excellent for clearing out weak enemies quickly early on in the event. Only obtainable from worlds naturally containing Corruption biomes. Does melee damage. For some insane damage, combine with the Fire Gauntlet.
• Paladin's Hammer. Ridiculously high damage, pierces infinitely, but has a short(ish) range. You can certainly manage without this, but later on you might find it useful to get it out for a few seconds to dish out some monster damage.
• Vampire Knives.
• Terra Blade. Best sword in the game. Fires a freebie projectile that hits up to 3 enemies. Doesn't autoswing on the console versions (but does on the PC version).
• Nimbus Rod. Fire-and-forget piercing damage. Nice when you have lots of enemies clustering above/below you as it will hurt all of them. You can miss out on this, but it's nice to have and relatively easy to acquire (certainly when compared with some of the items in this list!).
• Vampire Knives. Seriously.

PC users might also want to consider:

• Tempest Staff. Permanent minion as long as you stay alive, high damage (only the Staff of the Frost Hydra is higher, but that requires frequent resummoning). Drops from Duke Fishron.
• Optic Staff. If specialised in minions, you can have up to eighteen minions with this staff (nine pairs of eyes).

I can't stress enough how important the Vampire Knives are. They will keep you alive.

Armour

Assume the melee bonus for these sets.

• Turtle Armour is actually pretty good for this event due to the massive thorns bonus when taking melee damage (which Pumpking does do).
• Beetle Armour 'upgraded' version of the Turtle Armour, but forces you to choose between attack and defence. Also lacks the thorns damage of the Turtle Armour, but you can reach over 100 defence with this armour equipped.
• Chlorophyte Armour buffs your damage and critical strike rate (nice for the Vampire Knives that you really should have. Also provides some free damage in the form of the leaf crystal, and has decent defence to boot. You probably shouldn't try with anything less than this though.

Accessories

In terms of reforging, you would want either Warding, Violent or Menacing (or some combination thereof) depending how good the rest of your equipment is. Personally I go for 3 Warding and 2 Menacing.

• Ankh Shield. This is a complete pain in the backside to craft. However, it provides all of the following (and this is without even reforging it):
  • 4 defence
  • Immunity to knockback
  • Immunity to burning
  • Immunity to weakness
  • Immunity to broken armour
  • Immunity to poison
  • Immunity to bleeding
  • Immunity to slow
  • Immunity to confusion
  • Immunity to silence
  • Immunity to curse
  • Immunity to darkness
• Wings. Very useful for dodging attacks from both the Mourning Wood and Pumpking. Bear in mind that some wings are better than others. PC players should aim for the Fishron Wings due to the increased ascent speed, but really any type of wings will suffice.
• Bundle of Balloons. Again a pain to craft, but allows you to quadruple jump.
• Celestial Stone. Provides a bunch of nice buffs, including a 2 HP per second health regeneration buff. If you don't want to farm for the Sun Stone in order to craft this, a Moon Stone will suffice as the Pumpkin Moon event only happens at night anyway.
• Fire Gauntlet. Increases knockback slightly, gives you 9% additional melee damage and melee attack speed (so it buffs Vampire Knives and Scourge), and also sets things on fire. Nice to have, but don't fret too much if you don't have one. Also consider the Mechanical Glove.
• Star Veil. Increases the length of invulnerability after taking damage, and causes stars to fall when you take damage. Will pierce through all mobs until they hit the ground, so can be some nice free damage.
• Frozen Turtle Shell. Rare drop from Ice Tortoises that increases your defence by 30 while you're below 25% health. You shouldn't really need this if you got the Vampire Knives.

Obviously with only 5 accessory slots you won't be able to equip all of the above. Pick the ones that work best for you. Also don't forget that there's nothing stopping you using some of the other accessories that are ingredients for the ones listed above.

As with all events like this, the area you fight in is almost as important as the equipment that you wear. The first thing to do in this regard is ensure that you have a suitable arena in which to fight (read: big hole in the ground).

For this, you may want to spend some time acquiring the following:

• Heart Statue(s). When powered, they will spit out a Heart every 10 seconds.
• Star Statue(s). When powered, they will spit out a Mana Star every 10 seconds.
• 5 Second Timer. Use this to power the Heart and Star Statues.
• Wire. For wiring the timer to the statues.
• Wooden Platforms. You'll be standing on these a lot of the time. Mourning Wood projectiles will fall through platforms, giving you one less thing to dodge in the heat of battle.
• Assorted Lihzahrd traps. You can wire these up to timers if you really want, but that might cause some nasty lag if you have lots of traps spawning projectiles constantly. The flame traps are pretty nice, but have limited range, so mix them up with some Spiky Ball Traps and Super Dart Traps. Can also be wired to Yellow Pressure Plates so that players don't trigger them while collecting loot.
• A few buckets of lava. Creating a very shallow pond of lava at the base of the area will help nicely in thinning out the packs of enemies, while not destroying the loot (it needs to be very shallow - a pixel or two deep at most. Test it by throwing a Copper Coin into it, if it's destroyed it's too deep).

The above is by no means an exhaustive list, but it should give you something to aim for at least.