Beholster

 is a boss found in the Gungeon Proper.

Behavior

 * Fires two spreads of bullets towards the player followed by two rings of bullets in all directions.
 * Fires three fast moving small lasers at the player.
 * Sometimes this attack is replaced by 3 slow moving regular bullets.
 * This attack usually happens in conjunction with another attack.
 * Fires two missiles that home in on the player. These missiles can be destroyed by shooting them.
 * If the Beholster is Jammed, he shoots four missiles instead of two.
 * Charges up and fires a continuous laser while rotating towards the player.
 * This laser can be rolled over or blocked by cover.
 * The sweep of the beam will damage and frequently kill any Beadies caught in its path.
 * Spawns a Beadie.
 * Occasionally slightly moves towards the player after attacking a few times.

Strategy
Once you know Beholster's patterns, he really isn't that difficult. He has a relatively large hitbox, so accuracy isn't much of a problem.
 * When he fires spreads and rings, try not to dodge roll and simply walk in between the bullets, as you will be able to shoot more if you roll less.
 * The small lasers should be easy to dodge, they're only single shots. Try not to wedge yourself in the way of another attack by dodging these, though!
 * If he fires missiles, either focus on destroying the missiles first before attacking the Beholster or simply evade them while attacking - they explode by themselves eventually.
 * If he fires his laser, simply dodge roll through it or hide behind cover.
 * If a Beadie spawns, kill it before focusing on the Beholster, as its stray bullets coupled with the laser make a hard-to-dodge combo.
 * Its rockets can be destroyed instantly with any beam weapon.

Trivia

 * The Beholster is a reference to the Beholder of the Dungeons & Dragons role playing game.
 * The Beholster is one of only two enemies in the game to have a song in the soundtrack named after them (“The Beholster Don’t Blink”), the other being the Cubulon (“Die Cubulon Die”).
 * In the Enter the Gungeon comic, the Beholster appears as a 1st floor boss.