Bio
Queen Bee is a pre-Hardmode boss. She is summoned by breaking the Larva inside Bee Hives of the Underground Jungle, or by using an Abeemination anywhere within the Jungle. She can inflict the Poisoned debuff.
While Queen Bee is alive, the music Boss 5 will play. When Otherworldly music is enabled, the track Boss 1 (Otherworldly) will play instead.

Spawn Conditions

She is summoned by breaking the Larva inside Bee Hives of the Underground Jungle, or by using an Abeemination anywhere within the Jungle.

Stratigies
Queen Bee is capable of causing Poison if you get touched by it or by its stingers. While losing 2 health per second doesn't look like much, it can be significant over time. It's also important to not get poisoned because it halts Health regeneration, thus be always ready to heal with your Potions.
The Queen Bee has 4 distinct attack patterns:

1. It will fly left or right to you and charge three times;
2. It will hover above you and spawn tiny Bee minions;
3. It will behave like a normal hornet and fly around, shooting poisoning stingers at you.
4. It will gain defense and speed in expert mode

When it charges you, use platforms and/or a double jump or better to dodge upwards. You can stand perfectly still upon landing which gives you a short moment to regenerate health faster. If you can Dash, you can stand in its path and charge it just before it reaches you.
When it summons its bees, use a weapon that can pierce targets and aim for its backside to stop the bees the moment they spawn. If any bees manage to escape then use a Sword with a large swing to clear them out. The Queen is at its most vulnerable in this state, so use powerful weapons to deal significant amounts of damage.
If it's using the stinger-shooting phase, keep moving back and forth. If you do get hit by a stinger, the Poisoned debuff will last longer than when you touch the Queen Bee, so make sure to dodge it. Use a melee weapon, and try to track her movements by aiming where it's going to move.
If you're low on health and stayed in the Hive, remember to make use of the honey below you, which increases health regeneration, which will always stack with other regeneration buffs like Regeneration potions.