So Medium Magical Beast (Extraplanar)?
Some other ability scores for inspiration...
Monitor Lizard (M): Str 17, Dex 15, Con 17, Int 1, Wis 12, Cha 2
Basilisk (M): Str 15, Dex 8, Con 15, Int 2, Wis 12, Cha 11
Jhakar (M): Str 14, Dex 15, Con 19, Int 2, Wis 12, Cha 10
Komodo Dragon (M): Str 19, Dex 12, Con 17, Int 1, Wis 12, Cha 2