Bloodline Pretender

Changeling (This card is every creature type.)
As Bloodline Pretender enters, choose a creature type.
Whenever another creature you control of the chosen type enters, put a +1/+1 counter on Bloodline Pretender.

Phantatog

Sacrifice an enchantment: Phantatog gets +1/+1 until end of turn.
Discard a card: Phantatog gets +1/+1 until end of turn.

Auratog

Sacrifice an enchantment: Auratog gets +2/+2 until end of turn.

Psychatog

Discard a card: Psychatog gets +1/+1 until end of turn.
Exile two cards from your graveyard: Psychatog gets +1/+1 until end of turn.

Universal Automaton

Changeling (This card is every creature type.)

Sarcatog

Exile two cards from your graveyard: Sarcatog gets +1/+1 until end of turn.
Sacrifice an artifact: Sarcatog gets +1/+1 until end of turn.

Atogatog

Sacrifice an Atog creature: Atogatog gets +X/+X until end of turn, where X is the sacrificed creature's power.

Chameleon Colossus

Changeling (This card is every creature type.)
Protection from black
{2}{G}{G}: Chameleon Colossus gets +X/+X until end of turn, where X is its power.

Necratog

Exile the top creature card of your graveyard: Necratog gets +2/+2 until end of turn.

Phyrexian Metamorph

({U/P} can be paid with either {U} or 2 life.)
You may have Phyrexian Metamorph enter as a copy of any artifact or creature on the battlefield, except it's an artifact in addition to its other types.

Foratog

{G}, Sacrifice a Forest: Foratog gets +2/+2 until end of turn.

Avian Changeling

Changeling (This card is every creature type.)
Flying

Chronatog

{0}: Chronatog gets +3/+3 until end of turn. You skip your next turn. Activate only once each turn.

Changeling Berserker

Changeling (This card is every creature type.)
Haste
Champion a creature (When this enters, sacrifice it unless you exile another creature you control. When this leaves the battlefield, that card returns to the battlefield.)

Changeling Outcast

Changeling (This card is every creature type.)
Changeling Outcast can't block and can't be blocked.