Cheapest priced copy (Modern Horizons 2): $0.35 at Card Kingdom, near mint, their price list as of .
Mount Velus Manticore 
Enchantment Creature — Manticore · 3/4 · Common · Modern Horizons 2 · #136
At the beginning of combat on your turn, you may discard a card. When you do, this creature deals X damage to any target, where X is the number of card types the discarded card has.
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Modern Horizons 2 | 136 | Common | $0.35 | $0.49 |
2 rulings from Wizards of the Coast
- 18 June 2021If you do not discard a card, Mount Velus Manticore's reflexive triggered ability won't trigger.
- 18 June 2021The card types that can appear on a discarded card are artifact, battle, creature, enchantment, instant, kindred, land, planeswalker, and sorcery. Legendary, basic, and snow are supertypes, not card types; Manticore and Saga are subtypes, not card types.