With permission from SunMadcat, I have organized these monsters from his original wad into a pk3, fixed some bugs, and made a random monster replacer.
Spoiler: Corrected, Complete Summon Commands List (also included in the pk3) (Open)
Abbreviator
Abyss Mummy
Advocate, AdvocateRed, AdvocateGray, AdvocateGold
AirElemental, StormElemental
Andariel
ArabianSwordsman
Arachnoid
ArachnoShredder
ArchvileD64
Assassin
BaboonDemon, DuneBeast, DoomApe, TempleGuard
BarbarianAxeman, BarbarianAxemanGreen, BarbarianAxemanBrown,
BarbarianAxemanBlue, BarbarianAxemanBrownYellow, BarbarianAxemanBrownRed,
BarbarianAxemanDarkYellow
BaronAtArms
BaronJavelinThrower
BaronRifleman
BaronStalker
BarrelLegs
BeheadedKamikaze
BeheadedRocketter
Beholder
SwampEye
WarlockEye
BioMechanoidMinor, BioMechanoidMajor
Blunderbore
BruiserN64
BruteHammer
BurningDendroid, BurningDendroid2
CacodemonKing
CacoFish
CacoHands
CacoChaingunTron
CacoIronLich
CacoJoker
CacoLegs
CacoRingMaster
CacoShredder
CacoTron
CacoBrute
CacoPowerBrute
CacoNightmareBrute
CacoDemonHellBrute
CacoDamager
CacoBoss
CacoBossKing
CacoOrange
CentaurJavelinThrower
ClawViper, Salamander
ClericEnforcer, ClericEnforcer2
ClericEspadon, ClericEspadon2
ClericFirestorm
ClericHalberdier, ClericHalberdier2, ClericHalberdierGold
ClericLightBringer
ClericMaceman, ClericMaceMan2
ClericSerpentStaff
ClericWraithverge
CorvusBlackStaff
CorvusFrostfang
CorvusGauntlets
CorvusMace
CorvusPhoenixRod
CorvusSkullRod
CouncilMember, CouncilMemberGray, CouncilMemberRed
Crusader3, Crusader2
CubeBaron
CyberAvenger
CyberBaron64
CyberBishop
Cybermination
Cyberbrane
CyberChaos
CyberSnake
DaemoniumOverlord
DamTaacHead
DeathBrawler, DeathMauler, DeathSmasher, DeathBrigadier
DemonRascal
BaratusDemonsword
BaratusHammer
BaratusKoraxStaff
BaratusTimonAxe
Dendroid
DiabloMonster
DiarrhealCacodemon
DsparilMasked
Dreadnought
Efreet
Familiar
Elementamination
EliteWarrior
Embalmed
Enchanter, Enchanter2, Enchanter3, Enchanter4, Enchanter5
Enslaved
FanaticEnslaved
Overseer
EnslavedHalberdier
EttinAxeman
EttinSwordsman, EttinSwordsmanGold
EttinBerserk, EttinBerserkGold
Fallen, Carver, DevilKin, DarkOne
FallenShaman, CarverShaman, DevilKinShaman, DarkOneShaman
FatsoLegs, FatsoLegs2, FatsoLegs3, FatsoLegs4, FatsoLegs5
FlamingDendroid
GargoyleFourArmed
GargoyleTrap
GhoulDisciple
GhoulMaster, GhoulMasterGreen
GiantMosquito
Gloam
BaratusGloves
GnaarImp
GoldenAxeThief, SantaClaus
GreekGuard
Grotesque, StygianHag, FleshSpawner
GrotesqueWyrm, FleshBeast, StygianDog
HarpyImp
AkimboGuy
ArachnoSentinel, ArachnoSentinelPlasma
HebrewSpearman, HebrewSpearman2
HellSwarm, HellSwarmRed
HeresiarchBaron
Excubitor
HornedDemon
Horror, HorrorGreen
HorseArcher, HorseArcherRed
HumanArcher, HumanArcherRed
HumanArcherArmored, HumanArcherArmoredRed
HumanCrossbowman
HumanEnforcer, HumanEnforcer2
HumanHalberdier
HumanMaceman
HumanSpearman, HumanSpearmanRed
HumanSwordsman
HussiteFlailer
Hydra, HydraRed
ChaingunSentinel
ChaingunTurret, ChaingunTurretCeiling
ChaosMarine
WaterElemental
SlimeElemental
ToxinElemental
ImpArcher
ImpArcherArmored
ImpArcherUpgraded
CrossbowImpArmored
ImpFatsoDamager
ImpGunner
ImpMermaid
ImpMilitiaWinged
ImpMilitia
Izual
JumpJetMarine
Kamayuk, KamayukRed, KamayukBlue
KiAdiMundiSpear
KulrathKnight
KulrathSkeleton
LavaGolemSam
LavaGolemSamBig
LavaGolemSamBoss
LavaGolem, NukageGolem
LavaMummy, NukageMummy
Lich
LichDisciple
LichSaw
ImpMaceman
MadBaronCar
MadArchFlyer
MadFatsoCar
MadFatsoCar2
MageArcOfDeathMaster
MageBloodScourgeMaster
MageFrostShardsMaster
MageSerpentStaff
MageTriStaff
MancubusDude
MancubusDude2
Manticore, Scorpiore
MedusaArcher, MedusaArcher2, MedusaArcher3
MephistoVile
Merlin, Merlin2
MinionOfDestruction
MoonLord, MoonLord2, MoonLord3
MountedBaron
MechBaron
MechBaronCloak
MechDemon
MechImp
MummyHalberdier, MummyHalberdier2, MummyHalberdier3, MummyHalberdier4,
MummyHalberdier5
MummyDoom, MummyDoom2
MummyKnight, MummyKnight2, MummyKnight3, MummyKnight4, MummyKnight5,
MummyKnightGold, MummyKnightGold2, MummyKnightGol3, MummyKnightGold4,
MummyKnightGreen, MummyKnightGreen2, MummyKnightGreen3
MummyMage, MummyMage2, MummyMage3, MummyMage4, MummyMage5
MummySwordsman
MummyEnforcer
Naya2
Necromancer
Necro
Necron
NecronImmortal2
Necron2
NightElfAssassin
NightElfShredder
Nihlathak
OfficerChaingunner
PeasantFlail
PeasantFork
PeasantForkUpgraded
PeasantScythe
PeasantPistol
PeasantPistolSMG
PlasmaTurret, PlasmaTurretCeiling
PutridDefiler
QuadShotgunZombieMan
QuadShotgunZombiemanCaptain
QuillRat
RailBrainMad
ReaverDamager
DamagerReaverCaptain
RevenantD64
RollerCacodemon
RomeroInquisitor
RottingCacodemon
RottingCacodemonKing
SabreCat
SandRaider, SandRaider2
ShaolinMonk, ShaolinMonk2
ShieldImp
SkeletalMage
SkeletalWarrior
SkeletonRoyalGuard
SkeletonRoyalGuardCloak, SkeletonRoyalGuardCloak2, SkeletonRoyalGuardCloak3
SkullLich
SnakeRider
SnakeRiderLess, SnakeRiderLessRanged
SnowCaco
SnowDrifter
SoulKiller
SoulKillerRanged
SoulKillerShaman
UndeadStygianDoll
SpaceMarine
SSskull
TalRasha
TauScout, TauScoutBlue, TauScoutRed
TauWarrior
TOMsoldier
TOMtrooper, TOMTrooper2
TOMtrooperCaptain
Troglodyte, Troglodyte2
TroglodyteHoplite, TroglodyteHoplite2
TroglodyteShield, TroglodyteShield2
MarioBus
Unraveller
VenomLord
VoidDweller
WarRevenant
WereLizard
DiabloWraith
Cantor
Zakarumite, Faithful, Zealott, Zealot, Faithful2
Unfortunately, these monsters don't play nice With Russian Overkill. They have actors and sprites with the same names. This does work fine with my OPWeapons. Drop by my server in the next two weeks to give them a try.