Spy Kit

Equipped creature gets +1/+1 and has all names of nonlegendary creature cards in addition to its name.
Equip {2}

Miirym, Sentinel Wyrm

Flying, ward {2}
Whenever another nontoken Dragon you control enters, create a token that's a copy of it, except the token isn't legendary.

Mask of the Mimic

As an additional cost to cast this spell, sacrifice a creature.
Search your library for a card with the same name as target nontoken creature, put that card onto the battlefield, then shuffle.