"S" is for "Splicesaur — Dimetrog"

Splicesaur — Dimetrog

No. Enc.:  1d6 (2d6)
Alignment:  Neutral
Movement:  90' (30')
Armor Class:  5
Hit Dice:  9
Attacks:  3 or 1 (2 claws, 1 bite, or tail)
Damage:  1d6 / 1d6 / 1d10, or 1d8 + poison
Save:  L9
Morale:  10
Hoard Class:  VII
XP:  3,100

Dimetrogs are man-sized, nocturnal bipeds equally at home in tropical climes and barren wastelands.  Prominent sails jut from their backsides, as do elongated fangs from their snouts.

A dimetrog's piercing tail injects a deadly Class 15 venom.  And there is a 1 in 6 chance (on 1d6) that any given dimetrog can exhale a beam of withering heat, per the Energy Ray Physical Mutation [adjust XP accordingly].

Some travelers swear they've witnessed dimetrogs using primitive tools, and even Ancient artifacts....

Mutations:  Accumulated Resistance (Heat), Enhanced Vision (Night Vision), Toxic Weapon (Venom)