Kinjalli's Caller
Creature — Human Cleric
Dinosaur spells you cast cost 
less to cast.
The people of the Sun Empire worship the sun in three aspects. Kinjalli is the Wakening Sun, who created humans from clay and baked them in the sun's warmth.
Sara Winters
Ixalan (XLN)
• #18Rulings
If an effect refers to a "[subtype] spell" or "[subtype] card," it refers only to a spell or card that has that subtype. For example, March of the Drowned is a card that benefits Pirates and features Pirates in its illustration, but it isn't a Pirate card.
(wotc • 2018-01-19)
To determine the total cost of a Dinosaur spell, start with the mana cost or alternative cost you're paying, add any cost increases, then apply any cost reductions. The mana value of the creature remains unchanged, no matter what the total cost to cast it was.
(wotc • 2017-09-29)
Rulings
If an effect refers to a "[subtype] spell" or "[subtype] card," it refers only to a spell or card that has that subtype. For example, March of the Drowned is a card that benefits Pirates and features Pirates in its illustration, but it isn't a Pirate card.
(wotc • 2018-01-19)
To determine the total cost of a Dinosaur spell, start with the mana cost or alternative cost you're paying, add any cost increases, then apply any cost reductions. The mana value of the creature remains unchanged, no matter what the total cost to cast it was.
(wotc • 2017-09-29)