The obvious difficulty with minotaurs is that mythology kinda only had one of them. While I could have looked up how other fantasy worlds treat them -- Krynn, Dominaria, Azeroth -- that sounded terribly dull.
So, here are 6 random abilities (written for 5th edition) to give to minotaurs who stick to the classics: having horns, living in labyrinths, and eating people.
- This minotaur has a spatial rift hovering between its horns. You cannot meaningfully see through its luminescent surface, but it transmits sound, poorly. As a bonus action, the minotaur can cause an eldritch blast (+5 to hit, 120 ft., 1d10 force damage) to emanate from the rift. The rift persists after death, as long as the skull and horns remain intact. Touching the rift teleports you to a random location within the dungeon (4 in 6 chance), continent (1 in 6), or to a random plane (1 in 6). The destination changes over every 10 minutes.
- This minotaur has ritually eaten the flesh of an adventurer and absorbed its prowess. Roll a d8. On a 1-6 it has a random Fighting Style from the six available to the Fighter class. On a 7-8 it has 1d6 Sneak Attack and adds double its proficiency bonus to Stealth checks (for a total of +4). It wields the fallen adventurer's weapons. It has another ration of smoked human flesh that if eaten, bestows the same combat knowledge for 1 day. The ration detects as transmutation magic.
- This minotaur can telekinetically move loose rocks, unmortared bricks and the like. It rearranges its section of the labyrinth to confuse its prey, but may use its powers to aid the party if they offer sufficient tribute. As an action, it can move a quantity of stone that fits within a 10 ft cube, up to 30ft. Creatures hit by the slow-moving rocks take 1d6 bludgeoning damage, Dexterity DC 13 negates.
- This minotaur hears/smells around corners (blindsense 30 ft.) and throws vials of webbing (as the giant spider ability, and the vials are designed to ricochet off walls without breaking. Its horns are poisoned (one dose, as giant spider venom). Its giant spider farm is nearby. They are docile and affectionate.
- This minotaur shaman has ritually cut off its horns (no gore attack). It can cast bane, blindness/deafness, and lesser restoration. It has no spell slots, and instead casts spells by bloodletting itself with the horns (inflicting 1d6 damage/spell level). The horns function as a pair of +1 daggers. PCs who loot the horns can cast the above spells the same way. This requires attuning to the daggers. Bloodletting damage cannot be magically healed or recovered with Hit Dice, and goes away only with a long rest, though the obviously-deliberate cuts will show for at least a week. Higher level PCs may discover new spells that can be cast with the horns.
- This minotaur has necromantic powers, but only over cows. In combat this means it can animate armor that's predominantly leather, as the animate objects spell except it can affect worn/carried items. Animated armor worn by the PCs will tear itself off and begin attacking them. The minotaur also has a side gig resurrecting nearby farmers' cattle that perish from drought or disease.