Blaze

Blazes are found in the Blazing Fortress near the very top of the area, or to the right of the main entrance stairs. They can also be found on your Private Island if spawned by a Blaze Minion.

Blazes are also found in the Higher or Lower Dungeon Puzzle Room. These blazes are passive and spawn with 1000-9999.

Drops
They drop Blaze Rods which can be used to make Blaze Powder, an item used in brewing stands, or to make a Blaze Minion, which spawns Blazes and kills said spawned Blazes. The Blazes in the Blazing Fortress also have a chance of dropping a Blaze Hat; a decent hat for newer players.

How to Defeat
Blazes can be quite difficult for early game players, due to their ability to fly and maneuver, and how their fireballs can do serious damage. To hit blaze more effectively, a bow enchanted with Aiming is a very good choice, as the arrows will track down the Blazes. They also set the player on fire, so to prevent most of the damage, a, a Fire Talisman , or Armor that prevents fire damage, are highly recommended, to mitigate the fire damage that the Blazes inflict.

Trivia

 * Blazes that are killed drop 1-2 Blaze Rods, compared to vanilla minecraft 0-1