Hi,
I have a hypothetical question:

Alan controls Progenitor Mimic (PM#1) which isn't copying anything. It survives with Hall of Triumph choosing either green or blue. Alan then cast a second Progenitor Mimic (PM#2), choosing to copy the first when it resolve.

now the question is:
1) when we apply PM#2's replacement effect, letting it copy PM#1, we'll end up with PM#1's replacement effect (since it's still going to enter the battlefield). If we choose not to copy anything, it will become PM#1 with an upkeep trigger to create token copy of itself, right?

2) But if we choose to apply PM#1's replacement effects, that means, we CAN choose to copy ANY creature on the battlefield to copy via PM#1's replacement effect, right?

3) if yes, then PM#1 is still a legal option to copy again, right?

4) if we choose to copy PM#1 again, can we loop it? Getting a new replacement effect every time Alan choose to copy PM#1? or will it be considered as the same replacement effect and will not let you choose to copy again? (though in my opinion, it's a new one)

5) Can PM#2 end up with multiple upkeep trigger due to the loop?

so in short,
with PM#2 on the stack,
when it resolve, Alan choose to copy PM#1 with an upkeep trigger bonus due to PM#2's own replacement effect,
PM#1's replacement effect kicks in, allowing PM#2 to copy any creature on the battlefield,
Alan choose to apply it and copy PM#1 again, gaining another upkeep trigger (now 2)
will the newly chosen PM#1 (the second time it's being copied) create a new replacement effect?
Effectively allowing Alan to redo the loop any number of times, gaining a new upkeep trigger every time.
or will it be considered as the same replacement effect?

if it's a Clone on Clone, this might not have any significance, because there's no added ability/copiable value, so even if everytime we apply the replacement effect, it still allows us to copy another creature, unless we choose a different creature, we'll only end up with a simple Clone.

but Progenitor Mimic gives an upkeep triggered ability, which could be stacked, and thus will make a big difference if it does loop-able.

thanks in advance.
sorry if my question is confusing.

Originally posted by Progenitor Mimic:

Creature — Shapeshifter 0/0, 4UG (6)
You may have Progenitor Mimic enter the battlefield as a copy of any creature on the battlefield except it gains “At the beginning of your upkeep, if this creature isn't a token, put a token onto the battlefield that's a copy of this creature.”
Illus. Daarken

Hall of Triumph
Legendary Artifact, 3 (3)
As Hall of Triumph enters the battlefield, choose a color.

Creatures you control of the chosen color get +1/+1.
Heroes act without thought of glory or reward. Accolades are a consequence, not a goal.
Illus. Ryan Yee

Clone
Creature — Shapeshifter 0/0, 3U (4)
You may have Clone enter the battlefield as a copy of any creature on the battlefield.
He knows your strengths, your weaknesses, and the shape of that unfortunate birthmark on your backside.
Illus. Kev Walker

The answers to your five questions are, respectively, yes, yes, yes, yes, and absolutely not. Your newly-cast Progenitor Mimic cannot end up with multiple instances of the token-making ability in this manner, because each time you choose to copy the Progenitor Mimic on the battlefield, the token-making ability the resolving Mimic received from the previous copy effect is overwritten along with the rest of the Mimic's text by the new copy effect.

To illustrate, Progenitor Mimic starts out looking like this as it begins to resolve:

• Progenitor Mimic - {4}{U}{G}
  Creature — Shapeshifter
  You may have Progenitor Mimic enter the battlefield as a copy of any creature on the battlefield except it gains “At the beginning of your upkeep, if this creature isn't a token, put a token onto the battlefield that's a copy of this creature.”
  0/0

You then choose to apply the copy effect for the first time, copying the Mimic on the battlefield, which overwrites all the resolving Mimic's characteristics with a copy of the one on the battlefield: (I'm only illustrating the change in the text box because everything else remains the same.)

• Progenitor Mimic - {4}{U}{G}
  Creature — Shapeshifter
  You may have Progenitor Mimic enter the battlefield as a copy of any creature on the battlefield except it gains “At the beginning of your upkeep, if this creature isn't a token, put a token onto the battlefield that's a copy of this creature.”
  You may have Progenitor Mimic enter the battlefield as a copy of any creature on the battlefield except it gains “At the beginning of your upkeep, if this creature isn't a token, put a token onto the battlefield that's a copy of this creature.”
  At the beginning of your upkeep, if this creature isn't a token, put a token onto the battlefield that's a copy of this creature.
  0/0

You then choose to apply the new copy effect, copying the Mimic on the battlefield again, resulting in:

• Progenitor Mimic - {4}{U}{G}
  Creature — Shapeshifter
  You may have Progenitor Mimic enter the battlefield as a copy of any creature on the battlefield except it gains “At the beginning of your upkeep, if this creature isn't a token, put a token onto the battlefield that's a copy of this creature.”
  At the beginning of your upkeep, if this creature isn't a token, put a token onto the battlefield that's a copy of this creature.
  You may have Progenitor Mimic enter the battlefield as a copy of any creature on the battlefield except it gains “At the beginning of your upkeep, if this creature isn't a token, put a token onto the battlefield that's a copy of this creature.”
  At the beginning of your upkeep, if this creature isn't a token, put a token onto the battlefield that's a copy of this creature.
  0/0

If you apply the new-new copy effect, the Mimic will again end up looking like this, and so on and so forth. No matter how many times you apply the copy effect, each application overwrites the token-making abilities from the previous iteration, so you'll never get more than one.

Daniel Kitachewsky
L4, Paris, France
Rules NetRep