Sleipnir — Norse miniboss

Current implementation: checked against main at 78c7cd4 on 21 October 2026. Values below are defaults before room difficulty scaling unless stated otherwise.

Overview

Sleipnir is the eight-legged horse miniboss in dungeonThreeEnd. BossPhaseComponent switches from Phase 1 to Phase 2 at half of the actual maximum health. Default maximum health is 250 and base attack is 20; room difficulty can scale those values.

Phase	Behaviour	Main classes
Phase 1	Patrol a four-corner route relative to the spawn position; attack when the player is close.	PatrolTask, OneAttackTask
Phase 2	Earthquake and circling stampede attacks, with their own damage/timing rules.	EarthquakeAttackTask, StampedeTask

NPCFactory.createSleipnir(target, spawn) assembles the tasks, combat stats, health bar, BossPhaseComponent, EnemyDeathComponent, EnemyAnimationController and DustCloudAnimation. Phase-specific attack damage should be checked in the task implementations rather than inferred from the scaled base-attack field.

Animation and assets

The current sprite atlas is images/sleipnir/horse.atlas. The factory registers cardinal and diagonal movement animations, attack, chase, default and death animations. DustCloudAnimation provides the associated dust feedback. The updated sprites and dust integration were merged in PR #346; the earlier image below is retained as a design reference.

All Sleipnir sprites made by @Veenit254

https://github.com/user-attachments/assets/b90f0fd3-a0c9-438c-9178-714a64bb4c56

Reference to Smoke/Dust Animation

Death and achievement

Sleipnir uses the regular deferred enemy-death lifecycle. The room reports a SLEIPNIR kill for Eight Legs, No Escape. It must not clear while other tracked enemies remain alive.

Testing

Current test classes are SleipnirEnemyTest, PatrolTaskTest, OneAttackTest, EarthquakeAttackTest and StampedeTest. The previously listed OneAttackTaskTest, EarthquakeTaskTest and StampedeTaskTest are not the current class names.

Manual checks:

1. Enter the Norse end room and verify the spawn-relative patrol, health bar and eight-direction movement visuals.
2. Trigger a close-range Phase 1 attack, then cross half of the actual maximum health and verify the Phase 2 task switch.
3. Check earthquake/stampede timing, damage, attack animation and dust alignment in game.
4. Defeat Sleipnir and verify death cleanup, room completion and the boss achievement.

The diagrams below are retained as design-history references; the current class names and atlas path are given above.

UML Diagrams & Sequence Diagrams - Miniboss Lifespan

Sources and merged work

#233, #291, #346. Current source: NPCFactory.java, BossPhaseComponent.java, SleipnirEnemyTest.java.