You're walking down the street....

[Agarrita80]

 {Archon of the Triumvirate} it would eat me

{Undying Beast} or  {Pestilence Demon}

[IntoFire]

Pestilence Demon for sure!

{Diabolic Tutor} or  {Ravager of the Fells}?

[The1337Magician]

 {Ravager of the Fells}
{Infernal Tutor} or  {Infernal Kirin}

[Iandtormentor]

Tutor

{Abyssal Specter} or    {Death Pits of Rath}

[Agarrita80]

 {Abyssal Specter}

{Ravager of the Fells} or  {Fiery Hellhound}

[Ageniv]

Ravager definitely.
{abattoir ghoul} or {dance of the dead}

[lotrwk]

The ghoul
{Masticore} or  {Fire Servant}

[Agarrita80]

Masticore what's in it's mouth???

{Aquastrand Spider} or  {Plague Beetle}

[lotrwk]

Plague beetle
{Rakdos Shred-Freak} or {Tooth and Claw}

[Agarrita80]

 {Rakdos Shred-Freak}

{Cognivore} or  {Advent of the Wurm}

[Iandtormentor]

{Rakdos Shred-Freak}

{Cognivore} or  {Advent of the Wurm}

{cognivor}

{Clutch of Undeath} or  {Whipstitched Zombie}

[Agarrita80]

I'd go  {Whipstitched Zombie} the other guy is held back by some other force.

{Yavimaya Kavu} or  {Wolfir Silverheart}

[Mlerner12]

The firs one...

{Krenko, Mob Boss} or  {Talrand, Sky Summoner}?

[lotrwk]

Krenko
{Rakdos Guildmage} or {Skull Collector}

[Agarrita80]

This one was tough... I'd say the guild Mage though. I can outrun the other guy hopefully.

{Vulturous Zombie} or  {Screeching Harpy}