Phantasmal Image

You may have Phantasmal Image enter the battlefield as a copy of any creature on the battlefield, except it's an Illusion in addition to its other types and it has "When this creature becomes the target of a spell or ability, sacrifice it."

Quasiduplicate

Create a token that's a copy of target creature you control.
Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

Spark Double

You may have Spark Double enter the battlefield as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.

Pattern Matcher

When Pattern Matcher enters the battlefield, you may search your library for a card with the same name as another creature you control, reveal it, put it into your hand, then shuffle.

Island

Seven Dwarves

Seven Dwarves gets +1/+1 for each other creature named Seven Dwarves you control.
A deck can have up to seven cards named Seven Dwarves.

Mountain

Goblin Electromancer

Instant and sorcery spells you cast cost {1} less to cast.

Clone Legion

For each creature target player controls, create a token that's a copy of that creature.

Mirror March

Whenever a nontoken creature enters the battlefield under your control, flip a coin until you lose a flip. For each flip you won, create a token that's a copy of that creature. Those tokens gain haste. Exile them at the beginning of the next end step.

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Mechanized Production

Enchant artifact you control
At the beginning of your upkeep, create a token that's a copy of enchanted artifact. Then if you control eight or more artifacts with the same name as one another, you win the game.