Largest First-Turn Creature

[KulrathKnight]

{Lotus petal}
{dark ritual}
{dark depths}
{Vampire hexmage}

Hah! I love doing that to people in my EDH deck XD

{Dark Depths} is banned in EDH.

[Rpbarber]

No it's not. Look at the legalities.

[KulrathKnight]

Ah I stand corrected. My bad

[Umbra]

{Lotus petal}
{dark ritual}
{dark depths}
{Vampire hexmage}

Helloooooo nurse!

[Ieatfood7]

Dark ritual, ha! that's fine if you want to be realistic.

Turn one. Island, black lotus for green,  {Channel} for 19, giving you (19)GU. Play and activate {Doubling Cube} to have (28)GGUU. Play and activate  {Filigree Sages} to untapped the cube. Repeat to double your mana infinitely. With your infinite mana,  {Slime Molding} and  {Lightning Greaves} gives you an infinite sized attacker.

You said biggest, not most reasonable;). If you have a simian spirit guide or other source of red, replace lightening greaves with  {Burst of Speed} and replace slime moulding with  {Gelatinous Genesis} for infinite infinite/infinite creatures.

Edit:  {Chromatic Sphere}. That's how you get the red mana without using up a card.

[MarduArrow]

If we're being unrealistic i can top that; go second: opening hand-  {Mountain}  {Sol Ring} x2  {Black Lotus} x4 on draw step you get  {Emrakul, the Aeons Torn} play mountain, tap for sol ring, tap for sol ring 1 floating, play 4 lotuses, tap 2nd sol ring and use lotuses for a grand total of 15 mana, cast emrakul.

Taking this further, on the extra turn you get from emrakul you draw {Artillerize} swing with emrakul then tap sol rings and mountain to artillerize, end game

[Umbra]

Dark ritual, ha! that's fine if you want to be realistic.

Turn one. Island, black lotus for green,  {Channel} for 19, giving you (19)GU. Play and activate {Doubling Cube} to have (28)GGUU. Play and activate  {Filigree Sages} to untapped the cube. Repeat to double your mana infinitely. With your infinite mana,  {Slime Molding} and  {Lightning Greaves} gives you an infinite sized attacker.

You said biggest, not most reasonable;). If you have a simian spirit guide or other source of red, replace lightening greaves with  {Burst of Speed} and replace slime moulding with  {Gelatinous Genesis} for infinite infinite/infinite creatures.

4x black lotus 20x moxx just for the giggles, play  {Emrakul, the Aeons Torn}  {Ulamog, the Infinite Gyre} {Second Sunrise} until you get what you need. Oh! And  {Urabrask the Hidden} to attack first turn.

[MuggyWuggy]

"players drop all combos listed"
My first turn, flip table and /nerdrage
Insane {howl} of anger
Trample through store knocking everything over
Walk out of store stating you are a legendary mythic creature with 40/40 and haste as you leave.

[Harmon74]

I a fault pulled this off once in a store tourney back in the day (before the big DCI push). {Swamp}, {Dark Ritual} x3, {Baron Sengir}. Not that impressive nowadays but was enough to make the other guy scoop then.

That would only give you 7 mana because it would take 1 black to cast each dark ritual from the first.

Doh! Lol

[ibtrickey]

Why drop a big creature when you can just flash hulk win on turn 1 ?

What do you mean??