Making Monsters Smaller?

[frankthedm]

If I want to make a creature into one or more size categories smaller, can I just reverse the steps for increasing size category? Or is there something I should be aware of when trying to do this that might make the system breakdown?

The only reason I ask, is b/c the SRD (that I can find) does not mention making things smaller, only bigger.

The dungeonscape template is quite nice. It grants ability score bonuses to make up for 1/2 the str loss and all the con loss of de-advancing size along with INA foe all weapons. CR stays the same since while it is less akward in the dungeon, it lost reach and some attack and damage.

[sblock=Dungeonbred Beholder, Medium Aberration]Dungeonbred Beholder
Medium Aberration
Hit Dice: 11d8+44 (93 hp)
Initiative: +6
Speed: 5 ft. (1 square), fly 20 ft. (perfect)
Armor Class: 26 ( +3 Dex, +13 natural), touch 14, flat-footed 23
Base Attack/Grapple: +8/+6
Attack: Eye rays +11 ranged touch and bite +1 melee (2d4-2)
Full Attack: Eye rays +11 ranged touch and bite +1 melee (2d4-2)
Space/Reach: 5 ft./5 ft.
Special Attacks: Eye rays
Special Qualities: All-around vision, antimagic cone, darkvision 60 ft., flight
Saves: Fort +9, Ref +5, Will +11
Abilities: Str 6, Dex 16, Con 18, Int 17, Wis 15, Cha 15
Skills: Hide +17, Knowledge (arcana) +17, Listen +18, Search +21, Spot +22, Survival +2 (+4 following tracks)
Feats: Alertness(b), Endurance(b) Ability focus (eye rays), Great Fortitude, Improved Initiative, Iron Will
Environment: Underground
Organization: Solitary, pair, or cluster (3-6)
Challenge Rating: 13
Treasure: Double standard
Alignment: Usually lawful evil
Advancement: 12-16 HD (medium); 17-33 HD (large)

Antimagic cone(Su): See the Beholder entry in the Monster Manual for more information.

Eye Rays (Su): Each of a beholder's ten small eyes can produce a magical ray once per round as a free action. The DCs for this specimen’s rays is 19 due to ability focus (eye rays). See the Beholder entry in the Monster Manual for more information.

All-Around Vision (Ex): A beholder's many eyes give it a +4 racial bonus of Search and Spot checks, and it can't be flanked.

Flight (Ex): A beholder's body is naturally buoyant. This buoyancy allows it to fly at a speed of 20 feet and grants it a permanent feather fall effect (as the spell) with personal range.

Easy Maintenance (Ex): Needs food and water as if one size smaller. Does not need exotic diet.

Hardy (Ex): +2 racial bonus on saves vs. disease and poison. [/sblock]Here is a slightly advanced beholder that shouldn't die on the first hit.
[sblock=15 HD Durable Dungeonbred Beholder]
Durable Dungeonbred Beholder
Medium Aberration
Hit Dice: 15d8 +60 +15 (142 hp & Die Hard)
Initiative: +6
Speed: 5 ft. (1 square), fly 20 ft. (perfect)
Armor Class: 26 ( +3 Dex, +13 natural), touch 14, flat-footed 23
Base Attack/Grapple: +11/+9
Attack: Eye rays +14 ranged touch and bite +4 melee (2d4-2)
Full Attack: Eye rays +14 ranged touch and bite +4 melee (2d4-2)
Space/Reach: 5 ft./5 ft.
Special Attacks: Eye rays
Special Qualities: All-around vision, antimagic cone, darkvision 60 ft., flight
Saves: Fort +11, Ref +8, Will +11
Abilities: Str 6, Dex 16, Con 18, Int 17, Wis 15, Cha 16
Skills: Hide +21, Knowledge (arcana) +17, Listen +22, Search +25, Spot +26, Survival +2 (+4 following tracks)
Feats: Alertness(b), Endurance(b), Ability focus (eye rays), Great Fortitude, Improved Initiative, Iron Will, Improved toughness, Die Hard.
Environment: Underground
Organization: Solitary, pair, or cluster (3-6)
Challenge Rating: 14
Treasure: Double standard
Alignment: Usually lawful evil
Advancement: 16 HD (medium); 17-33 HD (large)

Antimagic cone(Su): See the Beholder entry in the Monster Manual for more information.

Eye Rays (Su): Each of a beholder's ten small eyes can produce a magical ray once per round as a free action. The DCs for this specimen’s rays is 22 due to ability focus (eye rays). See the Beholder entry in the Monster Manual for more information.

All-Around Vision (Ex): A beholder's many eyes give it a +4 racial bonus of Search and Spot checks, and it can't be flanked.

Flight (Ex): A beholder's body is naturally buoyant. This buoyancy allows it to fly at a speed of 20 feet and grants it a permanent feather fall effect (as the spell) with personal range.

Easy Maintenance (Ex): Needs food and water as if one size smaller. Does not need exotic diet.

Hardy (Ex): +2 racial bonus on saves vs. disease and poison.[/sblock]