Terarria guide: Defeating Duke Fisheron for the first time

Gee, how hard could it possibly be to defeat some flying freak of a fish (Duke fisheron)?

Insert deaths and overdosing on potions when trying to defeat Duke Fisheron. Of course this is with acquired gear at the time at this point (post-Plantera or even post-golem but Pre-lunar events ideally). With post-Moonlord gear, DF is a joke with good dodging, duh.

Dodging is the key to beating DF. Ideal mounts which can be gained at the time include the UFO mount (by defeating the martian madness which is doable with the right equipment and strategy) and any flying mount in general. The best bet is the UFO. Wings are a must if you don't have the flight mount. Any wing that you can get will do but try to get a better wing if possible.

For armor this depends on the class. For melee, beetle armor. For the ranger use the shroomite armor with the helmet related to the main projectile of choice. For the magic user, go for spectre armor with helmet of choice (Hood if dodging abilities are in doubt). I don't know what the summoner would use.

As for weapons... I don't have enough experience with melee or the other classes save for ranger. Good weapons are: Megashark/uzi paired with chlorophyte bullets (Homing attacks do great for DF who is REALLY fast and on the move!).
For bows: MAYBE daedric stormbow... maybe, repeaters (with good aim). For arrows go with holy arrows, hellfire arrows (solid damage output for both though holy arrows are harder to get and do greater damage).

To summon DF the truffle worm is needed (use as bait in the ocean). And it's a rare spawn that will flee when you get too close. So a surface mushroom biome + water candle will help a lot along with swinging the bug net like crazy when you see the truffle worm while charging at it. Rinse and repeat this until there's enough truffle worms.

For potions: Lifeforce potion (Fish in the hallow), Rage/wrath potion (Depending on what your world has, you can get both with many worlds. Rage is for crimson and wrath for corruption), ironskin, swiftness, endurance, food of any kind (For well fed buff), heartreach (nice to have but not needed), inferno (if you can get it!) and other potions depending on your class (Mana regen for the magic user and so on).

Gravitational potion is nice IF you can manage it without becoming confused (I found out that I did horribly with it!). This can be an alternative for the flight mount/wings.

Accessories (for all classes): Charm of myths (reduce potion cooldown and boost heath regen), speed boots (Frostspark, lighting etc), correlating damage boosting item (correlating emblem, magic quiver for bows, and so on), Worm scarf (EoW expert mode drop that you will ALWAYS get), Wings of choice, whatever else that will help.

Rangers: Magic quiver if using a bow, etc.

Magic users (including summoners): Mana flower, celestial cuffs, mana regeneration band, etc.

Melee: fire gauntlet, Flesh knuckles, mechanical glove, etc.

Try to get the warding prefix if you are bad at dodging. If you are good at dodging go for menacing or even lucky.

Once DF is summoned, dodge like a madman (I suggest moving in a circle-ish and avoiding the tornado things he summons.) and shoot like mad with the weapon of choice/autoswing weapon/whatever.

Hopefully you can outlast DF and kill him... hopefully. This will probably take several attempts, so stock up on the truffle worms.