300

Monsters with 300 ATK

 * 8-Claws Scorpion
 * A-Team: Trap Disposal Unit
 * Alien Grey
 * Ambulanceroid
 * Ameba
 * An Owl of Luck
 * Armed Ninja
 * Barrier Resonator
 * Bat
 * Blizzed, Defender of the Ice Barrier
 * Boost Warrior
 * Chrysalis Larva
 * Crimson Ninja
 * Crystal Beast Ruby Carbuncle
 * Cyber Kirin
 * Dancing Elf
 * Dandylion
 * Dark Plant
 * Darkbishop Archfiend
 * Decoy Dragon
 * Decoyroid
 * Des Dendle
 * Destiny Hero - Blade Master
 * Destiny Hero - Disk Commander
 * Dreamsprite
 * Evil Hero Infernal Prodigy
 * Flare Resonator
 * Fox Fire
 * Genex Power Planner
 * Gorgon Egg
 * Gren, Tactician of Dark World
 * Hard Armor
 * Herald of Green Light
 * Herald of Orange Light
 * Herald of Purple Light
 * Hero Kid
 * Jenis, Lightsworn Mender
 * Kahkki, Guerilla of Dark World
 * Kiseitai
 * Kuriboh
 * Kuribon
 * Laval Forest Sprite
 * Laval Miller
 * Legendary Six Samurai - Kageki
 * Leghul
 * Level Warrior
 * Magical Scientist
 * Magician of Faith
 * Magnetic Mosquito
 * Marshmallon
 * Milus Radiant
 * Miracle Flipper
 * Mokey Mokey
 * Mokey Mokey King
 * Morphtronic Remoten
 * Neo-Spacian Glow Moss
 * Nitro Synchron
 * Ooguchi
 * Petit Moth
 * Phantom Cricket
 * Prickle Fairy
 * R-Genex Oracle
 * Rafflesia Seduction
 * Reed Butterfly
 * Relinquished Spider
 * Rescue Cat
 * Ritual Raven
 * Sand Gambler
 * Shien's Squire
 * Silent Strider
 * Sinister Serpent
 * Skull Servant
 * Snap Dragon
 * Sonic Chick
 * Spirit Reaper
 * Stone Statue of the Aztecs
 * Sunny Pixie
 * Supay
 * T.G. Recipro Dragonfly
 * The White Stone of Legend
 * Thousand-Eyes Jellyfish
 * Tricular
 * Volcanic Counter
 * Wall of Ivy
 * Wattberyx
 * Wightmare
 * Winged Kuriboh
 * Winged Kuriboh LV10
 * Worm Apocalypse
 * Worm Linx

Monsters with 300 DEF

 * A Cat of Ill Omen
 * Ally Salvo
 * Amazoness Paladin
 * Armed Ninja
 * Assault Mercenary
 * Bite Shoes
 * Black Veloci
 * Blackwing - Breeze the Zephyr
 * Blade Rabbit
 * Blast Asmodian
 * Bone Mouse
 * Cactus Bouncer
 * Change Slime
 * Chrysalis Larva
 * Chrysalis Pantail
 * Cobra Jar
 * Cosmic Compass
 * Crimson Ninja
 * Crystal Beast Ruby Carbuncle
 * Dandylion
 * Dark Lucius LV4
 * Dark Resonator
 * Darksea Float
 * Des Wombat
 * Desertapir
 * Dice Jar
 * Djinn Prognosticator of Rituals
 * Dragunity Tribus
 * Drill Synchron
 * Elemental Hero Stratos
 * Elephun
 * Esper Girl
 * Evil Thorn
 * Fungi of the Musk
 * Gemini Soldier
 * Gigobyte
 * Gladiator Beast Darius
 * Gladiator Beast Secutor
 * Griggle
 * Grinder Golem
 * Hanewata
 * Hyena
 * Kattapillar
 * Key Mace
 * Left Arm of the Forbidden One
 * Left Leg of the Forbidden One
 * Magical Scientist
 * Metabo Globster
 * Mist Valley Soldier
 * Muka Muka
 * Mystic Lamp
 * Naturia Mosquito
 * Naturia Vein
 * Neo-Spacian Grand Mole
 * Noisy Gnat
 * Parasite Paracide
 * Queen's Double
 * R-Genex Oracle
 * Razor Lizard
 * Right Arm of the Forbidden One
 * Right Leg of the Forbidden One
 * Ritual Raven
 * Sasuke Samurai 2
 * Seismic Crasher
 * Shien's Footsoldier
 * Silent Insect
 * Sonic Chick
 * Steel Scorpion
 * T.G. Recipro Dragonfly
 * Test Ape
 * Test Tiger
 * The Kick Man
 * The Unhappy Girl
 * Tongue Twister
 * Tricular
 * Tuningware
 * Watapon
 * Worm Gulse
 * Wulf, Lightsworn Beast
 * X-Saber Palomuro
 * Yamatano Dragon Scroll