Cheapest priced copy (Fallout): $0.49 at Card Kingdom, near mint, their price list as of .
Synth Infiltrator 
Artifact Creature — Synth · 0/0 · Rare · Fallout · #40
Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
You may have this creature enter as a copy of any creature on the battlefield, except it's a Synth artifact creature in addition to its other types.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
4 printings · $0.49 to $8.99 at Card Kingdom
7 rulings from Wizards of the Coast
- 8 March 2024You can choose not to have Synth Infiltrator enter the battlefield as a copy of another creature. If you do, it will probably die due to having 0 toughness. (This is probably not the kind of innovation the Institute would approve of.)
- 8 March 2024If the copied creature is a token, Synth Infiltrator copies the original characteristics of that token as stated by the effect that created that token, with the noted exceptions.
- 8 March 2024If the copied creature is copying something else, then Synth Infiltrator enters the battlefield as whatever that creature copied, with the noted exceptions.
- 8 March 2024Except for being a Synth artifact creature in addition to its other types, Synth Infiltrator copies exactly what was printed on the original creature and nothing else (unless that creature is copying something else or is a token; see below). It doesn’t copy whether that creature is tapped or untapped, whether it has any counters on it or Auras and Equipment attached to it, or any non-copy effects that have changed its power, toughness, types, color, and so on.
- 8 March 2024Any enters-the-battlefield abilities of the copied creature will trigger when Synth Infiltrator enters the battlefield. Any “as [this creature] enters the battlefield” or “[this creature] enters the battlefield with” abilities of the copied creature will also work.
- 8 March 2024Improvise doesn’t change Synth Infiltrator’s mana cost or mana value, and it can’t reduce Synth Infiltrator’s cost below {U}{U}.
- 8 March 2024If the copied creature has {X} in its mana cost, X is 0.