Guardian Force

Guardian Forces (GF) are the summoned creatures of Final Fantasy VIII, and they are used by junctioning them to a character. The GF's govern major stat growth, elemental/status offence and defence, and the commands a character may use during battle. Each GF has a preset list of abilities they can learn, but through the use of certain items, the GF can learn additional abilities and forget those that were previously learned.

It is stated in-game that long-term junctioning of Guardian Forces causes memory loss to the user, so using them is not without risks.

GF Abilities
All abilities, either commands, stat boosts or support abilities, are learned via the GF's and junctioned to each party member for use in battle.

Junctionable
One of the GFs given to the students of Balamb Garden. It uses a thunder attack called Thunder Storm. It is fairly weak and is primarily used for its Card Mod ability, which allows the player to refine Triple Triad cards into items, and the Card move, which can turn weakened enemies into cards (which can be used to refine). It is able to refine items into Thunder/Wind magic and low-level magic to mid-level magic.
 * Quezacotl

The other GF given to Balamb students. Her attack is a ice-based attack called Diamond Dust. She is also fairly weak but her Doom ability can be used to kill stronger enemies that are vulnerable to Death magic. She is able to refine items into Ice/Water magic.
 * Shiva

A GF who lives in the Fire Cavern, not far from Balamb Garden. It is the objective of the pre-SeeD exam to defeat Ifrit within a chosen time limit. Upon defeat, Ifrit decides to join Squall due to his strength. Ifrit is the strongest GF you get for a while. He uses a fire attack called Hell Fire. Ifrit is useful due to it's strength increasing abilities such as Str+40% and Str Bonus. He can refine items into Fire magic (and oddly, Flare) and items into ammunition for Irvine's Limit Breaks.
 * Ifrit

The first GF that must be drawn from an enemy. You can draw her from Elvoret during the battle atop the Communications Tower in Dollet or from Tri-Point in Ultimecia's Castle if you missed her. She uses a non-elemental attack called Silent Voice that does moderate damage and induces silence upon the enemies that are susceptible. She is used for her Move-Find ability (reveals hidden save/draw points) and her Mag Bonus. Another ability of Siren's is Treatment, which cure status ailments. She can refine items into Life magic, Life medicine, or tools (for upgrading and refining).
 * Siren

A pair of GFs named Sacred and Minotaur that make their home in the Tomb of the Unknown King. If you defeat Sacred in combat, he will call Minotaur to help him and both must be defeated before they will join Squall and Co. He uses an earth-based attack called Brotherly Love that will not affect flying enemies. His top abilities are HP+80% and HP Bonus, but also has Defend, which allows a character to defend, and Cover, which allows a character to defend a low health ally. Brothers is the first GF that cannot refine anything.
 * Brothers

A GF that lives in a magic lamp. When the item Magical Lamp is used, the party will be transported to a battle with Diablos. Upon defeat Diablos will join you. He uses a gravity attack called Dark Messenger that does damage equal to Diablos' level in percentage to the enemies max HP. Notable abilities are Darkside (sacifice some HP to increase Str.), Mug (steal when attacking) and Enc-Half/None (deceases amount of random encounters). He can refine items into Time or Status magic.
 * Diablos

Can be drawn from Iguion in Deling City before fighting Edea or from Krysta in Ultimecia's castle if you missed it. Carbuncle's attack (Ruby Light) does not do damage, rather it casts Reflect on your entire party. Carbuncles important abilities include Vit Bonus, Counter (enables counter-attacking), and Auto-Reflect, which automatically casts reflect on the junctioned party member. It can refine recovery medicine from items.
 * Carbuncle

Can be drawn from NORG after opening the pod or Trauma in Ultimecia's Castle if you missed it. It uses a water element attack called Tsunami which is also capable of ejecting enemies from the battlefield. Leviathan's boost option is easier to get to max than the previous GFs. It has useful abilities including Spr Bonus, Auto-Potion, and Recover. It can refine items into Support magic or GF recovery medicine.
 * Leviathan

Can be drawn from either Fujin during your battle with Raijin and Fujin in Balamb or Red Giant in Ultimecia's Castle. It attacks with a wind-based move called Tornado Zone. Though not as powerful as other GFs, it is the first GF to give speed increases. It also has Absorb, which takes HP from the enemy and gives it to the caster, and Initiative, which lets the junctioned character start the battle with the attack gauge full. Pandemona cannot refine anything.
 * Pandemona

Can be found in the main hall of the Galbadia Garden during the assualt on Balamb. He must be defeated in combat for him to join. If you missed him, he can be drawn from Gargantua in Ultimecia's Castle. Cerberus' "attack" is called Counter Rockets and casts double and triple on all party members. Because of his Auto-Haste and Spd Junction abilities, he is useful for quick magic users. His Expendx2-1 ability makes it so double only uses one magic instead of two. Along with these, Cerberus also has the Alert ability which makes it so your party cannot be back-attacked. He also cannot refine anything.
 * Cerberus

A giant machine that must be drawn from either your second fight with Edea in Galbadia Garden or Catoblepas in Ultimecia's Castle. He uses a Holy attack called Holy Judgement which is very useful against undead enemies. Due to it's holy nature, it is good with healing. This is reflected in the abilities Revive, Med Data (increased effects of medicine), and Med LV Up (levels up medicine). It can also refine Mid-Level magic into High-Level magic.
 * Alexander

A train GF that must be assembled by acquiring a number of items and the Solomon's Ring. Doomtrain's attack, Runaway Train, does minor poison-based damage, but also inflicts every status ailment and depletes vitality. It has the abilities Darkside and Absorb (from Diablos and Pandemona, respectively) plus Auto-Shell and Junk Shop, which calls the weapon upgrading shop from the menu. It can also refine items into Forbidden (powerful) medicine.
 * Doomtrain

A powerful GF that must be fought in the Deep Sea Research Center to acquire. He'll ask 2 questions, and when you get them right a Ruby Dragon must be fought for each, and at the 3rd question a hidden option, "It's in our nature...", must be selected. His attack, Mega Flare, inflicts major non-elemental damage on all enemies. It has Diablos' and Cerberus' abilities Mug and Expendx2-1 as well as Auto-Protect, Move-HP Up and Rare Item, which increases the chance of getting a rare item from battle. He can also refine items into powerful Forbidden (the most potent) magic.
 * Bahamut

Acquired by defeating the Jumbo Cactuar on Cactuar Island. His 1000 Needles attack does 1000 extra non-elemental damage for every ten levels he gains. He is notable because he has HP, Str, Vit, Mag, and Spr Bonuses. He also has Pandemona's Initiative, Leviathan's Auto-Potion, Cerberus' Expendx2-1, Bahamut's Move-HP UP, Brothers' Defend, as well as his own Kamikaze. He also has Eva and Luck increases.
 * Cactuar

Joins after the party defeat Tonberry King, but to fight him, the player must defeat 20 Tonberries in a row. His Chef's Knife ability does minor non-elemental damage. He has the LV Down and LV Up abilities which decrease or increase the power of the enemy for decreased or added bonuses. He also has Initiative, Move-HP Up and Auto-Potion from previous GFs. He has four shop related abilities: Call Shop (visit a shop from the ability menu), Haggle (get a discount at shops), Sell-High (increase selling price), and Familiar (buy rare items in shop).
 * Tonberry

Can be drawn from either Ultima Weapon in the Deep Sea Research Center or Tiamat in Ultimecia's Castle. It is the most powerful GF in the game. Its attack is a solar attack called Eternal Breath, and it can easily exceed 9999 points of damage. Due to the attack's long duration, maxing out Eden's boost is relatively easy. It has the previous abilities Mad Rush and Darkside as well as a new one, Devour, which can be used to eat enemies. It also has Expendx3-1, which only uses one magic instead of three for triple. It can refine items into GF ability items.
 * Eden

Non-Junctionable
A warrior who appears on a six-legged horse at the start of battle. His attack Zantetsuken kills all enemies instantly. Odin can be found in the Centra Ruins on Disc 2 and Disc 3. He must be defeated within a time limit or else he will use Zantetsuken and kill your party. Odin appears until the end of Disc 3 where he is killed by Seifer Almasy.
 * Odin

Appears after Odin is killed in Disc 3; he has four attacks: Zantetsuken works the same as Odin's attack; Excalibur does strong non-elemental damage; Excalipoor does just 1 damage and Masamune does high non-elemental damage. He appears at random although, unlike Odin, he appears during battle and not before it. He can also appear in boss fights.
 * Gilgamesh

A Chocobo summoned using Gysahl Greens and leveled up through the Pocket Station device. Also, the first time your party goes to a Chocobo Forest and catches a chocobo, the Chocoboy will give Squall Boko as a gift to be summoned from then on and will follow the one you catch and ride on the world map.
 * Boko

Moomba is another GF that can only be acquired through the Pocket Station. Moombas are told to be members of the Shumi Tribe: when a Shumi comes to a certain age, they either mature or become a Moomba. Also, Moombas work in the D-District Prison.
 * Moomba

A fire elemental GF that can be obtained by using the item Phoenix Pinion in battle; she deals fire damage to all enemies and revives KO'd party members. She may also appear in some situations when the party has been KO'd. Phoenix Pinions are very rare and can be obtained in the Shumi Village and in Winhill among other places.
 * Phoenix

Another GF that can only be obtained by using the Pocket Station and completing a mini-game. Although they are mentioned briefly at one point in the game, this is the only appearance of a moogle in the game.
 * MiniMog