Not In Second Edition

My pseudo-dragon might have been ageless in AD&D, but he wouldn't have been in AD&D 2e.

It specifically states in the Monstrous Manual they average 15 years before succumbing to old age.

AD&D 4e, like OG AD&D doesn't specify a lifespan.

OG edition had a Dragon article that said they aged liked dragons, who don't die from old age.

The GURPS 4e conversion I made:

Pseudo Dragon (AD&D Monster Manual p.79)

124 Points

Attribute Modifiers: ST-8 [-80]; DX+4 (No Fine Manipulators -40%) [48]; HT+4 [40].

Secondary Characteristic Modifiers: SM-4.

Advantages: Affliction 1 (Magic Resistance 4, no hindrance +20%; Melee Attack -30%; Aura +80%) [17]; DR 6 (Cannot Wear Armor, -40%) [18]; Enhanced Move 1 (Air Speed 28) [20]; Innate Attack (Fatigue) 2d (Cyclic, 1 hour, 10 cycles, resistible, +90%; Follow-Up, Tail Striker, +0%; Resistible, HT-2, -20%) [34]; Flight (Winged, -25%) [30]; Impaling Striker (Tail) [8]; Invisibility (Mana Sensitive -10%) [36]; Magic Resistance 4 [8]; Mind Reading (Mana Sensitive -10%, Universal +50%, Telecommunication -20%) [36]; Nictitating Membrane 1 [1]; Reduced Consumption 2 [4]; See Invisible (Magical; Mana Sensitive -10%) [14]; Sharp Teeth [1]; Telesend (Mana Sensitive -10%, Sensory +20%, Universal +50%) [48]; Unaging [15].

Disadvantages: Cannot Speak [-15]; Dependency (Mana, Very Common, Constant) [-25]; Quadruped [-35] Social Stigma (Wild Animal) [-10].

Features:

Racial Skills: Brawling (E) DX [1]-14; Stealth (A) DX [2]-14; Tracking (A) Per+1 [4]-11.

I included unaging.  So there!

I love how the ability to give your companion the magic resistance is an affliction...

If you want to conform to the AD&D 2e stats change the Unaging [15] to 2 levels of Short Lifespan [-20] and the point total to 89 points.

PS: They have four legs and two wings.  Like all correctly depicted dragons.