Dragon, Deep Very Young (CR 6)

Small Dragon (Earth)
Alignment: Always Chaotic evil
Initiative: +0; Senses: blindsense 60 ft., darkvision120 ft., low-light vision, and keen senses
Languages: Draconic

AC: 19 (+1 size, +8 natural), touch 11, flat-footed 19
Hit Dice: 9d12+9 (67 hp)
Fort +7, Ref +6, Will +7
Speed: 40 ft., fly 150 ft. (average) , burrow 20 ft., swim 30 ft.
Space: 5 ft./5 ft.
Base Attack +15; Grapple +12
Attack: 1 Bite +11, 2 claws +6 melee; Breath +11 ranged
Damage: 1 bite 1d6+1, 2 claws 1d4+0, Breath weapon 4d8 (15)
Special Attacks/Actions: Breath Weapon
Abilities: Str 13, Dex 10, Con 13, Int 14, Wis 13, Cha 12
Special Qualities: True seeing, detect magic, charm immunity, cold and fire resistance 10, Snake form 3/day
Feats: #Feats: 4
Class Skills: Hide, Move Silently, Skill points: 24, and Swim
Advancement: 10-11 HD (Small)
Climate/Terrain: Underground
Organization: Solitary or clutch (2-5)
Treasure/Possessions: Double Standard

Source: Monster Compendium: Monsters of Faerûn

Breath Weapon (Su): A deep dragon's breath weapon is a cone of flesh-corrosive gas 4d8 damage, Reflex save for half (DC 15). Using a breath weapon is a standard action. Once a dragon breathes, it can't breathe again until 1d4 rounds later. A blast from a breath weapon always starts at the dragon's mouth and extends in a direction of the dragon's choice.

True Seeing (Su): Deep dragons have a permanent form of true seeing (as the spell).

Snake Form (Su): A very young deep dragon can assume its serpentine (legless) form three times per day. This form is the same size as the dragon, but able to move through smaller tunnels because it has no legs. The dragon's AC worsens by -6 in this form. It moves at 30 feet, flies at 10 feet (poor), and swims at 30 feet. It loses all claw attacks in this form, but can constrict opponents, dealing 1d8 damage.

If the dragon hits with this attack, it can make a free grapple check (without provoking an attack of opportunity). If it wins this check, it grabs and constricts its victim, automatically dealing the above damage every round until the opponent dies or breaks free.

Earth Subtype

This subtype usually is used for elementals and outsiders with a connection to the Elemental Plane of Earth. Earth creatures usually have burrow speeds, and most earth creatures can burrow through solid rock.