The alien is a race specific to Slash'EM Extended that start with a cursed loadstone in their inventory. They can be any role and alignment, but they start with a -20 alignment penalty and a -2 luck penalty.
Their maximum stats are as follows:
The alien is the "harder than hard" race; their level-up bonuses to health and mana are reduced in comparison to other races. An alien character will have a hard time no matter what role they chose, especially early on where the loadstone is a burden and the alignment/luck penalties prevent them from praying successfully. Allowing a nymph or other item-stealing enemy to remove the loadstone is a good strategy for a starting alien character. An alien Convict though, will have trouble with their encumbrance limit as they have both a loadstone and a heavy iron ball slowing them down.
If the loadstone can be uncursed (by finding a scroll of remove curse for example), the alien character may use a sling to fire it at a monster and deal quite solid damage, as the loadstone does a whopping d40 damage in Slash'EM Extended.