Just post here units that you'd like to see/make in starcraft II or starcraft mods. I'll start.

Protoss Foldship
Medium size, not really sure what it looks like though.
Weapon:
Voidfire payload, air to ground, burst laser range or so. Normal damage.
Abilities:
Hyper jump, 150 energy, teleports the Foldship to any location on the map.
Magnet lock, 100 energy, renders target unit immobile, but still able to attack. Does not work on air units.
Speed:
Around the same speed as a Scout, with the same sort of speed upgrade.
Tech tree:
Built at Stargate. Requires Templar Archives.
Purpose:
Harassment, air support.
Story:
Unable to gather the resources necessary to construct capital ships capable of interstellar travel, the Dark Templar found a way to channel the void in such a way that it could power a miniature warp core. Foldships lack the power to travel large distances at warp speeds, but were sufficient for the Dark Templar''s purposes at the time.

Zerg Hunter
Medium size, mutalisk-looking, low HP and armor

Weapon:
Acid Glaive- weak attack with a DoT on any attacked unit (maybe 1 damage/second). It cannot attack air.

Abilities:
Grab, 50 energy- grabs an enemy unit. This take 3 seconds. That unit cannot do anything, and is dropped after 10 seconds.
Drop, 0 energy (must have used Grab)- drops an enemy unit, doing damage to it and any units underneath. Damage done is based on the size of the dropped unit (marine would do 20 damage, a tank would do 40)

Speed: Fast

Tech: Morphed from Mutalisk, requires research at a Greater Spire.

Purpose: harrassment, ground support

New Zerg Units

Siegeling (Evolved from a zergling)
The Same size as the zergling and looks much the same except for the smaller front claws
Weapon:
Flame Breath
Abilities:
None
Speed:
Around the same speed as a zergling
Tech tree:
Requires Hive. Spawning Pool, Evolution Chamber
Purpose:
Zergling Support
Story:
The zerg saw the advantages of fire when they faced those pesky firebats during the resent wars in the Sector. Now the zerg have a nice way to make em crispy.

Protoss Ship (Couldn't think of anything better)
Size: Large, Very Large
Weapon: Disruptor Wave, Lots of them. Does minimal damage. But slows enemy units attack rate.
Armor + Shields: Heavy
Special Abilities:
Can Create ground or air units while on the move and can hold them inside (Even the air units) and has a very large capacity.
Recharges units shields that are inside it.

I actually tried this, and it worked the only problem was building the units on the move, it would crash. It wouldnt if it was stationary. Oh and the air units couldnt stay inside, unless I made them ground

Terran Pillager
Role: Mineral Stealer
Size: Small
Weapon: Attack with a weak laser, about half the attack of a wraith's, to both air/ground
Special Abilities: Able to mine minerals.
Able to load units, capacity 4
Speed: Scourge
Tech: Built at Starport, add-on required.
Story: The various Terran Organizations have grown weak in resources and pirates began stealing Minerals from others. A certain Pirate group created the Pillager, which was designed to carry SCVs and also carry minerals on it's own.

Zerg Hijacker (couldn't think of a better name)

Small, Zergling- or Broodling-sized ground unit
Weapon: none
Abilities: Infect. The hijacker disappears, the infected unit is given to it' owner, but it dies after a few seconds, exploding with splash damage
Speed: fast
Tech tree: no idea
Purpose: fun
Story: this creature is a by-product of zerg experiments to accelerate the assimilation of new organisms. the infestation succedes at first, but renders the infected organism highly unstable


Terran mine layer

Size: medium-large
Weapon: none
Abilites: can build and deploy varous kinds of mines. like
- spider mines (duh)
- emp mines (explode with EMP)
- decoy mines (cast Hallucination on the unit which triggered it)
- surveilliance beacon (not a mine, but a hidden detector)


Zerg Shoggoth
looks like a formless pile of living slime
Size: medium
Weapon: acid
Ablities: morph to creep (the unit just melts, turning into zerg creep)

This unit was going to be in my mod but was scrapped because balancing it would be way to hard.

XDF Counterspell (XDF is the human faction in the mod)
Medium size, would look like a sleek fightercraft. Flyer.
Weapons:
1: Light Laser: A retardedly weak laser cannon that can attack both land and air. Medium rate-of-fire, pretty short range, low damage,
2: Counterspell Array: Alt attack that randomly activates when attacking units with energy. Drains the target's energy and does damage equal to the energy drained. (In other words, randcondjmped Feedback effect.)
Tech tree: Becomes available with or immediatly after the Darkling (which is roughly equivilent to the Wraith).
Abilites: None, but might have been given Ensnare or something to make it more useful.
Role: Spellcaster-killing, obviously. Also good at killing active cloakers. It is also good at defending Warspires (Battlecruiser equivilent, but much stronger offensively, somewhat stronger defenses, and cost a lot more) from Darklings (which are active cloaking flyers that are good at killing Warspires).
Removed because: Not useful enough, too hard to balance, role overlap (somewhat), too much of a hard counter.

(On a side note, FTS, would giving it a spell or two make it useful enough to be re-added? I still liek the concept of an anti-caster unit like this.)