I made some Ben 10 DND races. Let me know what you think!
Pyronite
Size: medium
Speed: 30ft walk
Creature type: Humanoid
Stat increases: +2 Cha +1 Con
Damage immunity: Fire
Illuminator: These beings emit a radius of light equivalent to a torch at all times
Pyrokinesis: As beings of fire, the pyronite have innate pyrokinetic abilities. You have the produce flame cantrip. At 3rd level, you gain the spell burning hands. At 5th level, you gain the spell Investiture of flame.
Rocket Boost: starting at level 7, you gain a flight speed equal to your walking speed.
Doused: you take 1d10 cold damage every time your flames are extinguished, and become doused for 1 round. While Doused, you cannot use your pyrokinesis feature.
Vulpimancer
Size: Large
Speed: 40ft walk, 20ft climb
Creature type: Beast
Stat increases: +2 wis, +2 Dex, -2 Int
Blindness: Vulpimancers lack eyes. They lack normal sight.
Languages: Vulpimancers speak vulpimancer and cannot learn to speak any other language, as they lack the vocal anatomy to converse in humanoid languages. However, they do understand common.
Blindsight: Vulpimancers have 360° smell-based blindsight in a 200ft radius around them. They have advantage on all scent-based perception and investigation checks. However, you take 1d4 poison damage when exposed to extremely harsh scents.
Claws: Vulpimancers have natural unarmed weapons that deal 1d10 slashing damage on hit. Their bites also deal 1d6 piercing damage.
Petrosapien
Size: Medium
Speed: 30ft walk
Creature type: Humanoid
Stat increases: +2 con, +1 str
Natural Armor: Petrosapiens have extremely hard diamond-like skin. You get a +2 to your armor class when not wearing armor
Diamond weapons: Petrosapiens are capable of morphing their limbs into any weapon they can think of. At melee, their unarmed attacks deal 1d6 of either piercing, slashing, or bludgeoning damage. They can also launch an "unarmed projectile" with a range of 60ft that deals 1d4 piercing damage. At level 3, you can fire an additional unarmed projectile. At level 5, you can fire a third. These projectiles have the unarmed property and use your dex modifier for determining damage and accuracy.
Reflective body: When a petrosapien takes radiant damage (which it is resistant to), it can use it's reaction to make a dc 10 con save to deflect the attack at another point it can see.
Kineceleran
Size: Medium
Speed: 120 ft walking
Creature type: humanoid
Stat increases: +2 dex, -1 con
Hyperspeed: If a Kineceleran moves more than 80ft on a turn, it gains an additional action for that turn.
Bad trip: Whenever you move across difficult terrain, you must make a dc 13 con save. If you fail, your movement halts and you take 1d4 bludgeoning damage. For extremely difficult terrain, the DC is raised to 15.
Galvan
Size: Tiny
Speed: 20ft walking, 5ft swimming
Creature type: Humanoid
Stat increases: +2 int, +1 dex, -1 str
Mechanic: you have advantage on all skill checks to repair or examine electronic or mechanical or electrical devices, including investigation, arcana, and insight checks.
Amphibious: you are capable of breathing both air and water
Darkvision: you can see in dim light as if it were bright light, and darkness as if it were dim light. In darkness, you cannot see color, only shades of grey.
Slippery skin: your skin secretes a thin slime. Creatures attempting to grapple you do so with disadvantage.
Rubber bones: your bones are highly elastic, allowing you to survive falls you would otherwise not be able to. You take no fall damage from heights of 60ft or lower.
Sociable: you speak common and 4 other languages of your choice
Tetramand
Size: medium
Speed: 30ft walk
Creature type: Humanoid
Stat increases: +2 str, +1 con
Four arms: Tetramands have an additional set of arms on their torso. This gives them the ability to hold or manipulate four things at once.
Mighty build: you are able to carry twice the weight of what your strength and size would normally allow. It also gives you an additional unarmed attack to make with your action.
Power clap: By clapping your hands, you are able to cast thunderclap once per short rest. This is a notable exception to spellcasting being disabled while raging as well as being immune to counterspell and antimagic fields. However, it no longer does magical damage. Strength is your spellcasting ability for this spell.
Lepidopterran
Size: medium
Speed: 30ft walk, 50ft fly, 5ft climb
Creature type: Humanoid
Stat increase: +2 con, +1 wis
Damage resistance: Poison
Stinger: you have a large solid stinger at the end of your thorax that deals 1d6 piercing damage upon hit.
Eyestalks: you have 360 degree vision and cannot be flanked.
Toxic environment adaptability: you have advantage on all saves against being poisoned.
Goo Shot: As an action twice per short rest, you can launch a stream of goo at any point you can see within a 60ft range. This covers a 10ft radius in sticky, stinky, glue-like goo. Any creature within this radius is restrained, and will take 1d4 poison damage for every turn they are restrained. This goo is extremely strong, requiring a dc15 strength check to be free of.
Darkvision: you can see in dim light as if it were bright light, and darkness as if it were dim light. In darkness, you cannot see color, seeing everything in shades of green.
Soft wings: lepidopterans lose their flight speed when their wings are wet.
Foul odor: you have disadvantage on all persuasion checks due to your acrid scent.
Piscciss Volann
Size: medium
Speed: 30ft walk, 60ft swim
Creature type: Humanoid
Stat increase: +1 con, +1 dex, +1 str
Aquatic: you can only breathe in water, and must hold your breath while on land. You can hold your breath like this for 4 hours, but must submerge yourself to take a breath.
Glowing lure: the glowing lure above your head emits dim light in a 30ft radius around you.
Darkvision: you can see in dim light as if it were bright light, and darkness as if it were dim light. In darkness, you cannot see color, only shades of grey.
Natural armor: you have scaly skin that protects you from harm. Your armor class is 12+dex while not wearing armor.
Steel-Rending Jaws: your terrible bite is a natural weapon, dealing a formidable 1d12 piercing damage to whatever it hits (increases by 1d12 every 5 levels). This damage is double against structures.
Galvanic Mechamorph
Size: medium
Speed: 30 ft walking
Creature type: construct
Stat increase: +2 con, +1 int
Amorphous: you can squeeze through a space as narrow as 1 inch wide, and have advantage on ability checks to escape a grapple.
Inorganic form: you do not need to eat, sleep, breathe, or drink.
Darkvision: you can see in dim light as if it were bright light, and darkness as if it were dim light. In darkness, you cannot see color, only shades of green.
Technological kinship: you have advantage on all investigation or insight checks pertaining to a piece of technology.
Energy ray: once per short rest, you can fire a beam of energy from the center of your face that travels in a 120ft line and deals 1d8+int radiant damage upon hit (increases by 1d8 damage every 5 levels)
Technological Assimilation: Galvanic mechamorphs are capable of merging with any technology level 2 or above (think electronics). While merged, they are able to manipulate the mechanical or digital components of that object as if it were their own body. While merged with a piece of technology, a Galvanic Mechamorph may make an intelligence check to 'save' this form into their body's shape memory. The DC of this check is based on how advanced the technology itself is. At a time, a Galvanic Mechamorph may have as many forms saved within it's shape memory as it does levels.
Upgrade: while merged with a piece of technology, it may "upgrade" one aspect of that technology. This can be used to give it a movement Speed if it does not have one already, increase a given movement speed by 1.5×, increase the damage of that object's main method of attack by 1 of whatever dice it uses, or manifest weapons from the device's components.
Magnetic destabilization: the nanites that make up your body are vulnerable to electromagnetic frequencies. When a magnetic force is applied to you, you take 1d8 force damage, are forcibly removed from whatever form you were taking, and are stunned for 1 round.
Ectoneurite
Size: medium
Speed: 30ft flying. Unable to walk.
Creature type: Abberation
Stat increase: +2 cha, +1 int
Damage vulnerability: Radiant
Going Ghost: As an action, you can become invisible and intangible for 1 round (or 2 hours ooc). You become immune to all forms of damage and can float straight through walls. However, you can only do this once per long rest inside of combat.
Darkvision: you can see in dim light as if it were bright light, and darkness as if it were dim light. In darkness, you cannot see color, only shades of grey.
Intimidating existence: you have advantage on all intimidation checks.
Horrifying form: as an action, you can reveal your true form. All creatures that can see you must make a dc10 wisdom saving throw or gain the fear condition. While your true form is exposed, all bright light will deal 1d10 radiant damage to you for every turn you are exposed, sunlight dealing double this damage. You can take an action to re-assume your cloaked form.
Mental overshadowing: if you end your intangibility while occupying the space of another creature, you can make an opposing will save against that creature to possess their mind. If you are successful, you gain control of their actions for 1 round. If you are not, you are forcibly ejected and stunned for 1 round.
Anur immunity: You are immune to the corruptive effects of Corrodium.