Cheapest priced copy (Ixalan): $0.35 at Card Kingdom, near mint, their price list as of .
Tilonalli's Knight 
Creature — Human Knight · 2/2 · Common · Ixalan · #169
Whenever this creature attacks, if you control a Dinosaur, this creature gets +1/+1 until end of turn.
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Ixalan | 169 | Common | $0.35 | $0.49 |
2 rulings from Wizards of the Coast
- 29 September 2017If you don’t control a Dinosaur as Tilonalli’s Knight attacks, its ability won’t trigger at all. If you don’t control a Dinosaur as the ability of Tilonalli’s Knight resolves, that ability has no effect.
- 29 September 2017Once the ability of Tilonalli’s Knight resolves while you control one or more Dinosaurs, Tilonalli’s Knight gets +1/+1 for the rest of the turn even if you no longer control a Dinosaur later in the turn.