Gah! I meant Giant Pterosaur (changed now).
Just to be clear we're on the same page (or rather post) we're doing this
Ti-khana Giant Pterosaur, with the
Ti-khana War Pterosaur and
Ti-khana Venomwing Pterosaur to come later.
I added one hit dice and made d10 as pteranodon is size M.
So it's Large with 4d10 Hit Dice? That's in the ballpark for an average battlefield mount comparable to a Warhorse, or rather a flying one like a Giant Eagle or Hippogriff, which is what we're aiming for.
I'd suggest giving it a +3 Strength bonus like a Riding Horse or Giant Eagle rather than the +2 it's got. It needs to be strong enough to lug around a rider. Maybe STR 16 (+3) like the oversized bird of prey?
DEX and CON are allright, although I could see the Giant Pterosaur having the same DEX 15 as its regular sized cousin.
As for the mental stats, hmm… I don't think it should be quite as smart as the INT 6 Ti-khana Deinonychus which we intended to be exceptionally cunning, although I'd accept the War Pterosaur being that smart the Giant Pterosaur is more an everyday mount cum warbeast.
Maybe INT 6 for War, INT 5 for Giant, INT 4 for the birdbrained Venomwing?
WIS 10 seems off. I know a regular 5E Pteranodon has WIS 9 but frankly that's silly, as Pteranodons had quite well developed brains and sensory organs. Certainly there's no sound justification for it having a Wisdom lower than a Plesiosaurus!
I'd go for WIS 12 (+1).
CHA 11 is fine by me.
Or how about swapping the odd/even around for WIS 13, CHA 10 like the TK Deinonychus?
Hmm… I quite like that.
Which boils down to the following suggestions:
Giant Ptero #1A: STR 16, DEX 17, CON 12, INT 5, WIS 12, CHA 11.
Giant Ptero #1B: STR 16, DEX 15, CON 12, INT 5, WIS 12, CHA 11.
Giant Ptero #2A: STR 16, DEX 17, CON 12, INT 5, WIS 13, CHA 10.
Giant Ptero #2B: STR 16, DEX 15, CON 12, INT 5, WIS 13, CHA 10.
Any winners among those?