Acquiring Missed GFs...
	Various Steam Achievements...

If you missed any GF on your way through the game, you can get them during Disc 4 at Ultimecia's Castle. After defeating Sphinxaur, choose to unlock the Draw ability. You'll then be able to draw the following GFs from the corresponding Bosses.

Unlockable	How to unlock
Alexander	Catoblepas
Carbuncle	Krysta
Cerberus	Gargantua
Eden	Tiamat
Leviathan	Trauma
Pandemona	Red Giant
Siren	Tri-Point

Achievement	How to unlock
Collecting is Half the Battle	Complete 50% of the Bestiary.
Filling Up the Grotesquerie	Complete the entire Bestiary.
For a Rainy Day	Save up 50,000 gil.
Glutton for Arms	Obtain every weapon in Eureka, the Forbidden Land.
Gone Adventuring with the Wind	Defeat Djinn and obtain the Wind Crystal.
I, My, Me, Mine	Open every treasure chest.
Jack of All Trades	Attain level 99 with all jobs for all characters.
My Little Esper	Obtain a summonable creature.
No Such Thing as Too Many	Obtain all the summonable creatures.
Nose for Treasure	Open 50% of all treasure chests.
One Sword to Slay Them All	Obtain the Ultima Weapon from the Legendary Smith.
Quelling the Tremors	Defeat Titan and obtain the Earth Crystal.
Release the Kraken	Defeat Kraken and obtain the Water Crystal.
Some Like It Hot	Defeat Salamander and obtain the Fire Crystal.
Steely Resolve	Defeat Iron Giant.
Warriors of Light	Defeat the Cloud of Darkness.
When I Grow Up I Want to Be...	Attain level 99 with any job.
Who Wants to Be a Gillionaire?	Save up 500,000 gil.