Ran out of space in the OP due to fixing tables, so I have to start moving the 3 original dragons out of it. So without further ado

Deep Trench Dragon
Dragon (Aquatic, Water)
Environment: Undersea trenches (any aquatic)
Organization: Wyrmling, very young, young, juvenile, and young adult: solitary or clutch (25); adult, mature adult, old, very old, ancient, wyrm, or great wyrm: solitary, pair, or family (12 and 25 offspring)
Challenge Rating: Wyrmling 4; very young 5; young 6; juvenile 9; young adult 12; adult 14; mature adult 17; old 19; very old 20; ancient 22; wyrm 23; great wyrm 25
Treasure: Triple standard
Alignment: Always neutral evil
Advancement:Wyrmling 78 HD; very young 1011 HD; young 1314 HD; juvenile 1617 HD; young adult 1920 HD; adult 2223 HD; mature adult 2526 HD; old 2829 HD; very old 3132 HD; ancient 3435 HD; wyrm 3738 HD; great wyrm 40+ HD.

They have draconic scales which are a bright silver-blue at birth and darken till by the great wyrm stage they could be called black (although in the proper light they reveal a little blue). Even so their bodies are reminiscent of eels except for two massive arrays of fin-wings similar to the fins of a flying fish and for their two massive arms which end in crustacean-like claws. Their heads are definitely draconic and right behind their heads are their first fins, although periodically along their body more can be found. They hate bronze dragons but rarely interact as they spend most of their time at the sea bed only rarely coming to surface and even then almost always in the middle of the ocean. Their lack of legs reduces them to slow crawling when on land and their sub-par wings hinder them in the air making them slower and less agile than other breeds of dragons.
They often war with krakens over territories and have been known to rule over sahagin kingdoms. They often demand tribute from those who would pass through their territories and this sometimes brings them in conflict with sea dwelling storm giants. The giants have been known to use young deep trench dragons as slaves, but so too have mature dragons been known to capture and enslave storm giants. Most mated pairs include one older and obviously dominant member and usually do not last long as they have a compulsion to dominate the area and hate each other probably more than any other competitors they have in the seas.

Deep Trench Dragons by Age
Age Size HD (hp) Str Dex Con Int Wis Cha BAB/Grp Atk Fort Ref Will Breath Weapon Damage Breath Weapon DC Frightful Presence DC
Wyrmling M 6d12+12 (51) 17 10 15 6 9 8 +6/+9 +9 +7 +5 +4 2d8 15 -
Very young L 9d12+27 (85) 21 10 17 8 11 10 +9/+18 +13 +9 +6 +6 4d8 17 -
Young L 12d12+36 (114) 25 10 17 8 11 10 +12/+23 +19 +11 +8 +8 6d8 19 -
Juvenile L 15d12+60 (157) 29 10 19 10 13 12 +15/+27 +23 +13 +9 +10 8d8 21 -
Young Adult H 18d12+90 (207) 31 10 21 10 13 12 +18/+36 +26 +16 +11 +12 10d8 24 20
Adult H 21d12+105 (241) 33 10 21 12 15 14 +21/+40 +30 +17 +12 +13 12d8 25 22
Mature Adult H 24d12+144 (300) 33 10 23 12 15 14 +24/+43 +33 +20 +14 +15 14d8 28 24
Old G 27d12+189 (364) 35 10 25 14 17 16 +27/+51 +35 +22 +15 +17 16d8 30 26
Very Old G 30d12+240 (435) 37 10 27 16 19 18 +30/+55 +39 +25 +17 +21 18d8 33 29
Ancient G 33d12+297 (511) 39 10 29 18 21 20 +33/+59 +43 +27 +18 +23 20d8 35 31
Wyrm G 36d12+360 (594) 41 10 31 20 23 22 +36/+63 +47 +30 +20 +26 22d8 38 34
Great Wyrm C 39d12+390 (643) 43 10 31 20 23 22 +39/+71 +49 +31 +21 +28 24d8 39 35

Deep Trench Dragon Abilities by Age
Age Speed Initiative AC Special Abilities Caster Level SR
Wyrmling 20 ft., swim 100-ft, fly 100 ft. (clumsy) +0 16 (+6 natural) touch 10, flat-footed 16 Immunity to fire and pressure, blindsense 360-ft, powerful claws, weak wings
Very young 20 ft., swim 100-ft, fly 100 ft. (clumsy) +0 18 (1 size, +9 natural) touch 9, flat-footed 18 -
Young 20 ft., swim 100-ft, fly 100 ft. (clumsy) +0 21 (1 size, +12 natural) touch 9, flat-footed 21 -
Juvenile 20 ft., swim 100-ft, fly 100 ft. (clumsy) +0 24 (1 size, +15 natural), touch 9, flat-footed 24 Tojinada Sight 1st
Young adult 20 ft., swim 150-ft, fly 100 ft. (clumsy) +0 26 (2 size, +18 natural), t 8, FF 26 DR 5/magic 3rd 19
Adult 20 ft., swim 150-ft, fly 100 ft. (clumsy) +0 29 (2 size, +21 natural), t 8, FF 29 - 5th 21
Mature adult 20 ft., swim 150-ft, fly 100 ft. (clumsy) +0 32 (2 size, +24 natural) t 8, FF 32 DR 10/magic 7th 23
Old 20 ft., swim 200-ft, fly 150 ft. (clumsy) +0 33 (4 size, +27 natural), t 6, FF 33 Transformation of the Deep 9th 24
Very old 20 ft., swim 150-ft, fly 150 ft. (clumsy) +0 36 (4 size, +30 natural), t 6, FF 36 DR 15/magic 11th 26
Ancient 20 ft., swim 150-ft, fly 150 ft. (clumsy) +0 39 (4 size, +33 natural),t 6, FF 39 Blackwater Tentacle 13th 28
Wyrm 20 ft., swim 150-ft, fly 150 ft. (clumsy) +0 42 (4 size, +36 natural) t 6, FF 42 DR 20/magic 15th 30
Great wyrm 20 ft., swim 150-ft, fly 150 ft. (clumsy) +0 41 (8 size, +39 natural) t 2, FF 41 Blood to Water 17th 32
*Can also cast spells from the Blackwater, Ocean, and Storm domains as arcane spells.

Breath Weapon (Su): A line of superheated liquid, deals fire damage.

Powerful Claws: Deals claw damage as a dragon one size category larger. Its claws, though, are not opposable in its natural form (no fingers or thumbs)

Weak Wings: Their wings are half-way between wing and fin making them less useful in combat or agile in flight than those of most dragons. As such they deal wing damage as a dragon one size category smaller and postpone gaining wing attacks until they reach one size category larger than is normally required.

Skills: Appraise, Jump, and Swim are class skills for Deep Trench Dragons.