Nidoqueen - Exeggutor - Jolteon - Taorus - Kabutops - Moltres
"The Queen" "Dr. Eggman" "Blitzkrieg" "Barcelona" "Altomare" "Phoenix"
Nidoqueen: Ground/Poison
Exeggutor: Grass/Psychic
Jolteon: Electric
Tauros: Normal
Kabutops: Water/Rock
Moltres: Fire/Flying
Type: Weakness / Resistance
Normal: 0 / 1
Fighting: 2 / 3
Flying: 1 / 2
Poison: 1 / 2
Ground: 3 / 2
Rock: 1 / 1
Bug: 1 / 2
Ghost: 1 / 1
Steel: 0 / 2
Fire: 1 / 2
Water: 2 / 1
Grass: 1 / 2
Electric: 2 / 3
Psychic: 1 / 1
Ice: 2 / 1
Dragon: 0 / 0
Exeggutor: Grass/Psychic
Jolteon: Electric
Tauros: Normal
Kabutops: Water/Rock
Moltres: Fire/Flying
Type: Weakness / Resistance
Normal: 0 / 1
Fighting: 2 / 3
Flying: 1 / 2
Poison: 1 / 2
Ground: 3 / 2
Rock: 1 / 1
Bug: 1 / 2
Ghost: 1 / 1
Steel: 0 / 2
Fire: 1 / 2
Water: 2 / 1
Grass: 1 / 2
Electric: 2 / 3
Psychic: 1 / 1
Ice: 2 / 1
Dragon: 0 / 0
"The Queen" the Nidoqueen
Earthquake / Blizzard / Thunder / Body Slam
Normally I would choose Nidoking over Nidoqueen, as Nidoking has higher offenses (albeit lower defenses) and is considered the better of the two. However, since Nido is acting as my lead, I wanted stronger defenses over offenses to hopefully tank one or two more hits from opposing Pokemon. This is Nidoqueen's standard moveset (Thunder over Thunderbolt for more power), allowing her to hit a variety of Pokemon that may oppose her.
"Dr. Eggman" the Exeggutor
Sleep Powder / Psychic / Explosion / Mega Drain
Exeggutor here serves as a great precursor to both Kabutops and Moltres, as its Sleep Powder can buy them time to set up Swords Dance or Agility, respectively. By itself, Exeggutor is one of the stronger Grass-type Pokemon in RGBY. Psychic is its main attacking move, with Mega Drain to regain any lost health (largely useful when the opponent cannot attack due to Sleep), and Explosion if circumstances are dire.
"Blitzkrieg" the Jolteon
Thunderbolt / Thunder Wave / Body Slam / Double Kick
Usually a late-game Pokemon, Jolteon is near the end of this roster. Thunderbolt and Body Slam both have a chance to paralyze, but Thunder Wave can be used if the opponent is a big enough threat. Double Kick for coverage against Normal types. Although Jolteon has lackluster defenses, it's high Special and Speed make it very useful as a late-game Cleaner, although a well-timed Earthquake could send it's HP down in a hurry.
"Barcelona" the Tauros
Body Slam / Hyper Beam / Earthquake / Blizzard
Taorus acts as a late-game sweeper, boasting high attack and speed (and a high critical hit ratio) and decent defenses. Body Slam can paralyze most threats, while Hyper Beam, Earthquake and Blizzard can hit almost all Pokemon for huge HP loss. As fighting Pokemon aren't very common in RGBY, Tauros should be mostly unopposed due to the Normal's type advantage in RGBY.
"Altomare" the Kabutops
Swords Dance / Body Slam / Surf / Hyper Beam
Provided Kabutops has a turn to set up Swords Dance (A sleeping Pokemon left over from Exeggutor being the primary option), it can become a surprisingly good late-game sweeper. Surf hits opposing Ground and Fire type Pokemon hard, while Body Slam can paralyze Kabutop's threats, namely Venusaur and Exeggutor.
"Phoenix" the Moltres
Agility / Fire Spin / Fire Blast / Hyper Beam
Moltres's Agility+Fire Spin combination is deadly in RGBY. When used correctly, Fire Spin can render opponents completely useless, provided Moltres attacks first. Fire Blast helps burn opponents and shatter their offensive capabilities, namely Rhyhorn and Rhydon, while Hyper Beam hits hard on Pokemon that resist fire-type moves.