Spelunky is © 2008, 2009 Derek Yu and Mossmouth, LLC, and is used under the [Spelunky User License v1.1b](https://spelunky.ai/LICENSE.txt). spelunky.ai is an unofficial fan project, not affiliated with or endorsed by Mossmouth. The game and its assets may not be sold. Music by George Buzinkai and Jonathan Perry; sound effects made in SFXR. From Spelunky Classic 1.1, © 2008, 2009 Derek Yu and Mossmouth, LLC. # Alien From the spelunky.ai wiki: . Verified against the spelunky.ai port [v0.1.10](https://github.com/851-labs/spelunky/releases/tag/v0.1.10) on 27 October 2026. *For the mothership's boss, see [Alien Boss](https://spelunky.ai/wiki/alien-boss).* The Alien is a small monster of the Ice Caves in Spelunky Classic that parachutes out of a destroyed UFO and paces its ledge, hurting only on contact. ![A small green alien with one big eye, walking](https://spelunky.ai/wiki/media/17b72a4951674638/sprites/sAlien/anim%404x.png) | Alien | | | --------- | ----------------------------------------------------------------- | | Health | 1 hit point[^1] | | Damage | 1 heart[^2] | | Speed | 1 pixel per step[^3] | | Behaviour | Paces its ledge, never stepping off it[^4] | | Objects | `oAlien`, `oAlienEject` | | Found in | The Ice Caves (Out of UFOs a thrown item or monster destroys)[^5] | No level generation makes Aliens: each comes out of a [UFO](https://spelunky.ai/wiki/ufo) in the Ice Caves that a thrown item or a thrown monster destroys, 1 time in 3. It shoots up out of the wreck, opens a parachute and drifts down, then walks back and forth on the ledge where it lands. An Alien doesn't chase or attack the player; touching it costs him 1 heart, and with 1 hit point, it dies to any hit. ## Behaviour **Clip: Alien parachute.** An alien ejected from a UFO the player has destroyed opens its parachute, drifts down to a ledge, lands and walks about. ([video](https://spelunky.ai/wiki/media/17b72a4951674638/clips/alien/parachute/clip.mp4)) When a thrown item or a stunned monster thrown at a UFO destroys it, the UFO has a 1 in 3 chance of ejecting an Alien[^5][^6]. The Alien shoots straight up at 6 pixels per step, slowing by 0.5 each step and trailing flames, until it stops or meets a ceiling[^7][^8]. Then it opens its parachute and drifts down at 2 pixels per step (60 per second) and 1 pixel per step to one side, which it picks at random, until a wall stops it going sideways[^9][^10]. When it reaches the ground, or a web, it becomes an Alien on its feet[^11][^12]; one that drifts out of the level is gone[^13]. The clip shows an Alien parachuting from a UFO the player has destroyed, landing and walking off. On the ground, an Alien sets off walking in a random direction at 1 pixel per step (30 per second), and turns around at walls and at the edges of its ledge, so it never walks off one[^14][^15]. On a ledge with a wall or a drop on both sides of it, it stands still, facing away from the wall[^16]. It stops to stand for 20–50 steps (0.67–1.67 seconds) with a 1 in 100 chance each step, then sets off again in a random direction[^17][^18]. An Alien only acts while it's on screen or just off it, its parachute a little further below the screen[^19][^20]. ## Damage When the player touches an Alien without landing on it, he loses 1 heart, is knocked away from it, and blinks, invincible, for 30 steps (1 second), as with most monsters[^21]. An Alien still under its parachute does the same[^22]. ## Defeating **Clip: Alien stomped.** The player walks off a ledge and lands on an alien standing in a hole below, killing it. ([video](https://spelunky.ai/wiki/media/17b72a4951674638/clips/alien/stomp/clip.mp4)) An Alien on its feet has 1 hit point, so any of these kills it, leaving no body[^23]: | Way | Damage | | | ------------------------------------------------------------------ | -------------------------------------------------------------------------- | ----- | | Whip | 1 hit point | [^24] | | Machete | 2 hit points | [^24] | | Stomp (landing on it) | 1, plus 1 for every 16 steps of falling; three times that with Spike Shoes | [^25] | | A thrown item moving faster than 2 pixels per step, such as a Rock | 1 | [^26] | | A stunned monster thrown into it | 1 | [^27] | | A Shotgun or Pistol bullet | 4 hit points | [^28] | | A Bomb's explosion | 30 hit points | [^29] | | A Spear Trap's spears | 2 | [^30] | | Falling onto Spikes | Kills it | [^31] | | Standing in Lava | Kills it | [^32] | | Ending up inside solid ground | Kills it | [^33] | The clip shows the player landing on an Alien and killing it. Under its parachute, an Alien isn't one of the monsters weapons, items and explosions hit: only landing on it kills it, and that counts as killing an Alien[^34]. Aliens killed count toward the player's kills, and the screen between levels draws an Alien icon for each[^35][^36]. One that Spikes, Lava or a Spear Trap killed doesn't count[^37][^38][^39]. ## Locations Aliens appear only out of UFOs, and level generation makes UFOs only in the Ice Caves[^5][^40]. A UFO destroyed any way but by a thrown item or monster ejects none[^41]. In custom levels, it's the level editor's tile `a`[^42]. ## Tips - An Alien never steps off its ledge, so one on a platform stays on it. - Under its parachute an Alien can only be stomped, so it's safer to wait until it lands than to whip at it. - A UFO brought down by the Whip, a stomp, a bullet or a Bomb never releases an Alien. ## Trivia - The parachuting Alien has a state for deploying its parachute that's never used: it goes from shooting up straight to drifting down[^43][^44]. - Its touch event starts with a comment copied from the code most monsters share, though it isn't one of them: ```gml objects/oAlienEject/collision_oPlayer1.gml:1 // jumped on - oCaveman, oManTrap replaces this script with its own ``` `objects/oAlienEject/collision_oPlayer1.gml:1`, from `spelunky.gmk`, Spelunky Classic 1.1's source, © 2008, 2009 Derek Yu and Mossmouth, LLC ([Spelunky User License v1.1b](https://spelunky.ai/LICENSE.txt)). ## FAQ ### How much damage does an Alien do in Spelunky Classic? 1 heart per touch. An Alien never attacks: touching it, walking or still under its parachute, costs the player 1 heart, knocks him back and makes him invincible for 30 steps (1 second). ### How do you kill an Alien in Spelunky Classic? Hit it once: it has 1 hit point, so a Whip hit, a stomp, a thrown Rock, a bullet or a Bomb kills it. While it's still drifting down under its parachute, only landing on it does. ### Where do Aliens come from in Spelunky Classic? From [UFOs](https://spelunky.ai/wiki/ufo). A UFO destroyed by a thrown item or a thrown monster has a 1 in 3 chance of ejecting an Alien, which parachutes down and walks off where it lands. Level generation makes none. ### Does the Alien chase the player in Spelunky Classic? No. Its movement never looks at where the player is: it walks back and forth along its ledge, turning at walls and edges, and stops at random. ## See also - **Damaged by:** Whip, Machete, Spikes, Stomping[^25], Throwing[^26], Shotgun[^28], Pistol[^28], Bomb[^29], Spear Trap[^30], Lava[^45] - **Related:** [UFO](https://spelunky.ai/wiki/ufo) ## References [^1]: `objects/oAlien/create.gml:10` [^2]: `objects/oEnemy/collision_oCharacter.gml:25` [^3]: `objects/oAlien/step.gml:66` [^4]: `objects/oAlien/step.gml:39-75` [^5]: `objects/oItem/step.gml:331-340` [^6]: `objects/oEnemy/step.gml:243-251` [^7]: `objects/oAlienEject/create.gml:6` [^8]: `objects/oAlienEject/step.gml:7-18` [^9]: `objects/oAlienEject/create.gml:21` [^10]: `objects/oAlienEject/step.gml:19-38` [^11]: `objects/oAlienEject/step.gml:23-27` [^12]: `objects/oAlienEject/collision_oWeb.gml:1-2` [^13]: `objects/oAlienEject/other_outside.gml:1` [^14]: `objects/oAlien/step.gml:30-58` [^15]: `objects/oAlien/step.gml:66-67` [^16]: `objects/oAlien/step.gml:59-65` [^17]: `objects/oAlien/step.gml:69-74` [^18]: `objects/oAlien/step.gml:30-38` [^19]: `objects/oAlien/step.gml:3-5` [^20]: `objects/oAlienEject/step.gml:1-3` [^21]: `objects/oEnemy/collision_oCharacter.gml:14-27` [^22]: `objects/oAlienEject/collision_oPlayer1.gml:19-32` [^23]: `objects/oAlien/step.gml:13-23` [^24]: `objects/oEnemy/collision_oWhip.gml:1` [^25]: `objects/oEnemy/collision_oCharacter.gml:6-13` [^26]: `objects/oItem/step.gml:341-348` [^27]: `objects/oEnemy/step.gml:252-259` [^28]: `objects/oBullet/collision_oEnemy.gml:16` [^29]: `objects/oExplosion/collision_oEnemy.gml:12-19` [^30]: `objects/oEnemy/step.gml:98-104` [^31]: `objects/oEnemy/step.gml:108-124` [^32]: `objects/oEnemy/step.gml:65-74` [^33]: `objects/oAlien/step.gml:8-11` [^34]: `objects/oAlienEject/collision_oPlayer1.gml:1-18` [^35]: `objects/oAlien/step.gml:16-21` [^36]: `objects/oTransition/alarm_0.gml:209-213` [^37]: `objects/oEnemy/step.gml:68` [^38]: `objects/oEnemy/step.gml:101` [^39]: `objects/oEnemy/step.gml:120` [^40]: `scripts/scrEntityGen.gml:338-360` [^41]: `objects/oUFO/step.gml:6-16` [^42]: `scripts/scrCreateTileObj.gml:205-208` [^43]: `objects/oAlienEject/create.gml:15-19` [^44]: `objects/oAlienEject/step.gml:11-16` [^45]: `objects/oEnemy/step.gml:63-74` ### Source code - `objects/oAlien/create.gml` - `objects/oAlien/step.gml` - `objects/oAlienEject/create.gml` - `objects/oAlienEject/step.gml` - `objects/oAlienEject/collision_oPlayer1.gml` - `objects/oAlienEject/collision_oWeb.gml` - `objects/oAlienEject/other_outside.gml` - `objects/oEnemy/create.gml` - `objects/oEnemy/step.gml` - `objects/oEnemy/collision_oCharacter.gml` - `objects/oEnemy/collision_oWhip.gml` - `objects/oItem/step.gml`