Tonberry King
Elemental: None
Starting Level: 30
Starting HP: 2596
Where do I get it? You have to beat 18 or more Tonberrys at the Centra Ruins. After beating enough of them the Tonberry King will appear. When you beat him he'll join you. For full quest click here.

GF Attack: Chef's Knife: This attack only affects one enemy and you don't get to choose which one either. Its also really weak at first but over time it does get better. The animation is kinda short too so you won't be able to do a lot of boosting.

Useful Abilities: Once you have this guy its a lot easier to buy things. With the Familiar ability every item gets added to every shop you visit and then there's the Call Shop ability which lets you revisit any shop you've been to before right through the menu instead of having to travel to them.
Ability List
Ability

Magic
GF
Draw
Item
LV Down
LV Up
Eva+30%
Luck+50%
Initiative
Move-HP Up
Auto-Potion
SumMag+10%
SumMag+20%
SumMag+30%
GFHP+10%
GFHP+20%
GFHP+30%
Boost
Haggle
Sell-High
Familiar
Call Shop
AP Needed

Learned
Learned
Learned
Learned
Learned
Learned
Learned
Learned
160
200
150
40
70
140
40
70
140
10
150
150
150
200
Leads To...

Nothing
Nothing
Nothing
Nothing
Nothing
Nothing
Nothing
Nothing
Nothing
Nothing
Nothing
SumMag+20%
SumMag+30%
Nothing
GFHP+20%
GFHP+30%
Nothing
Nothing
Sell-High
Nothing
Call Shop
Nothing