There are spells or magic items that can temporarily stall a dragon's growth?

[Samael Morgenst]

Aussirachthend ("icecream", in Draconic) is a wyrmling white dragon of Tiny size but colossal+ ambitions. Unusually smart for his breed (he has elite - player character - ability scores) he was raised in captivity among the frost giants and sold to a fairly powerful Wizard to serve as familiar.
More cunning and patient than the average white, he managed to cajole some favour toward his master, to the point of being taken as apprentice and cohort rather than mere pet familiar. He risked his life adventuring and trained relentlessly, quickly gaining several class levels.

Yet now he's approaching the fifth year of life and he realizes that if allowed to grow normally, his innate powers will hamper his possibilities of advancement through training ( in game terms, the increased LA will forbid him from gaining those last class levels before hitting the ECL 20 cap ).

Icecream is not against growing at all - he already envisions himself as an advanced Great Wyrm - but he needs just a few more years of adventuring to complete his formative stage.

So, there's any spell / item that could do the trick?


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Aussirachthend
Male wyrmling white dragon
Sorcerer 1/ Mystic 4/ Geomancer 5
Effective Character Level: 15 (3 hit-dice, LA+2)
Tiny dragon (cold)
Hit Dice 3d12+1d4+4d8+5d6+13 (69 hp)
Initiative +4
Speed 65 ft., burrow 30 ft., swim 60 ft., fly 150 ft. (average)
Armor Class 14, touch 12, flat-footed 14
Base Attack +9; Grapple +2
Attack +12 melee (1d4+1, bite)
Full Attack +12 melee (1d4+1, bite), +7 melee (1d3+1, 2 claws);
Space/Reach 2-1/2 ft./0 ft. (5 ft. with bite)
Special Attacks: breath weapon (Su): 15-ft. cone, 1d6 cold, Reflex DC 12 half
Special Qualities: blindsense 60 ft., darkvision 120 ft., icewalking, immunity to cold, magic sleep effects,and paralysis, low-light vision, vulnerability to fire
Alignment: Neutral Evil
Saves: Fort +12, Ref +5, Will +15
Str 12, Dex 10, Con 12, Int 10, Wis 16, Cha 14.
Skills: Hide +26, Listen +6, Search +4, Sense Motive +6, Spot +6, Swim +20, Spellcraft +4, Knowledge (arcana) +4, Knowledge (religion) +4, Knowledge (nature) +4, Concentration +5
Feats: Improved Initiative, Iron Will, Alternative Source Spell, Craft Wondrous Item, Theurgic Creationist
Class Features: Spellshield (replaces Summon Familiar), Domain (Pride), spell versatility 4, ley lines +1 (aquatic), drifts (spots and stripes, adaptive skin, swift as an elk, fish gills)