Glasspool Shore

Glasspool Mimic

You may have this creature enter as a copy of a creature you control, except it's a Shapeshifter Rogue in addition to its other types.

Glasspool Mimic // Glasspool Shore

Clever Impersonator

You may have this creature enter as a copy of any nonland permanent on the battlefield.

Kimahri, Valiant Guardian

Vigilance
Ronso Rage — At the beginning of combat on your turn, put a +1/+1 counter on Kimahri and tap target creature an opponent controls. Then you may have Kimahri become a copy of that creature, except its name is Kimahri, Valiant Guardian and it has vigilance and this ability.

Aggressive Biomancy

Create X tokens that are copies of target creature you control, except they have "When this token enters, it fights up to one target creature you don't control."

City of Death

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after VI.)
I — Create a Treasure token.
II, III, IV, V, VI — Create a token that's a copy of target non-Saga token you control.

Progenitor Mimic

You may have this creature enter as a copy of any creature on the battlefield, except it has "At the beginning of your upkeep, if this creature isn't a token, create a token that's a copy of this creature."

Cackling Counterpart

Create a token that's a copy of target creature you control.
Flashback {5}{U}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Elminster's Simulacrum

For each opponent, you create a token that's a copy of up to one target creature that player controls.