Overview
When you control Academy Manufactor, Camellia, the Seedmiser, Chatterfang, Squirrel General, Peregrin Took, and Ygra, Eater of All and an effect would create one or more tokens under your control, multiple replacement effects can apply and they interact multiplicatively — the final tokens created (and subsequent triggered abilities) depend on which replacement effects you apply first. Chatterfang applies to tokens created under your control even if you don't control the effect that created them [Ruling 2025-01-24], Peregrin only applies if you are the one creating the tokens [Ruling 2023-06-16], and Chatterfang's ability applies to Clue/Food/Treasure tokens as well [Ruling 2021-06-18].
Step 1Illustrative starting event: a spell or ability you control would create one Treasure token under your control.
Step 2If you apply Academy Manufactor first: the single Treasure creation is replaced with creating one Clue, one Food, and one Treasure (3 tokens) because Academy Manufactor replaces creation of any Clue/Food/Treasure you would create.
Step 3After Academy's replacement, apply Peregrin Took: Peregrin's replacement sees one or more tokens being created under your control (and you are the one creating them in this example) and adds an additional Food token, giving Clue + Food + Treasure + Food (4 tokens).
Step 4Finally apply Chatterfang: Chatterfang's replacement sees those 4 tokens being created under your control and replaces that event with creating those 4 tokens plus 4 1/1 green Squirrel tokens, so you end up with 4 non-Squirrel tokens and 4 Squirrel tokens (8 tokens total) [Ruling 2025-01-24] [Ruling 2021-06-18].
Step 5Alternative order — apply Peregrin first: the single Treasure becomes Treasure + Food (2 tokens). Apply Academy next: each Treasure/Food creation is replaced by one of each (Clue/Food/Treasure), so each of the 2 original token creations becomes 3 tokens, producing 6 tokens total. Apply Chatterfang last: Chatterfang adds 6 Squirrels, so you end with 6 non-Squirrel tokens and 6 Squirrel tokens (12 total) [Ruling 2025-01-24] [Ruling 2021-06-18].
Step 6If Chatterfang is applied earlier, it only makes squirrels equal to the number of tokens at the time it is applied; tokens created later by other replacements won't retroactively cause more squirrels to be created by that earlier application [Ruling 2025-01-24].
Step 7Any Foods that actually reach the battlefield can later be sacrificed; sacrificing one or more Foods will cause Camellia, the Seedmiser's triggered ability to create a 1/1 green Squirrel token for that sacrifice event, and Ygra will get +1/+1 counters whenever a Food is put into a graveyard from the battlefield (two +1/+1 counters per Food) because Ygra makes other creatures into Food artifacts and cares about Foods going to the graveyard.
Resolution
If you are the player creating the tokens, all three replacement effects (Academy Manufactor, Peregrin Took, and Chatterfang) can apply to the same token-creation event; the order you apply those replacement effects (the controller of the event chooses the order when multiple replacement effects you control apply) determines the final counts. For example, starting from a single Treasure token creation: applying Academy then Peregrin then Chatterfang produces 4 non-Squirrel tokens (Clue, Food, Treasure, extra Food) and 4 Squirrels (total 8 tokens), while applying Peregrin then Academy then Chatterfang produces 6 non-Squirrel tokens (two sets of Clue/Food/Treasure) and 6 Squirrels (total 12 tokens). Chatterfang will add squirrels equal to the number of tokens being created at the time its replacement is applied [Ruling 2025-01-24] and it applies to Clue/Food/Treasure tokens as well [Ruling 2021-06-18]. Peregrin's replacement only applies if you are the one creating the tokens (so it won't apply if some other player’s spell or ability causes tokens to be created under your control unless you are the creator) [Ruling 2023-06-16].
