Cheapest priced copy (Modern Horizons 2): $0.35 at Card Kingdom, near mint, their price list as of .
Prophetic Titan 
Creature — Giant Wizard · 4/4 · Uncommon · Modern Horizons 2 · #209
Delirium — When this creature enters, choose one. If there are four or more card types among cards in your graveyard, choose both instead.
• This creature deals 4 damage to any target.
• Look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in a random order.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
2 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Modern Horizons 2 | 209 | Uncommon | $0.35 | $0.49 |
| Modern Horizons 2 | 373 | Uncommon | $0.35 | $0.49 |
3 rulings from Wizards of the Coast
- 18 June 2021The card types that can appear in a graveyard are artifact, battle, creature, enchantment, instant, kindred, land, planeswalker, and sorcery. Legendary, basic, and snow are supertypes, not card types; Giant and Wizard are subtypes, not card types.
- 18 June 2021Prophetic Titan's ability checks the number of card types in your graveyard as it's put on the stack. If you have four or more types in your graveyard at that time, but fewer than four as it resolves, you will still get to use both modes chosen.
- 18 June 2021If only the first mode is chosen, or if both modes are chosen, and the chosen target is illegal as the ability tries to resolve, the ability won't resolve and none of its effects will happen.