Syphoncrawler

[ghostchild]

Syphoncrawler
 
Creature - Insect Horror
Pay 2 life: Syphoncrawler gains haste until end of turn.
Pay 2 life: Syphoncrawler gains trample until end of turn.
Pay 2 life, sacrifice a creature: Syphoncrawler gets +2/+2 until end of turn.
4/2

Current Version:
Syphoncrawler
 
Creature - Insect Horror
Pay 4 life: Syphoncrawler gains trample until end of turn.
Pay 4 life: Syphoncrawler gains haste until end of turn.
Sacrifice a creature: Syphoncrawler gets +2/+2 until end of turn.
4/2

[Anusien]

Haste and Trample are out of color for black.  Sacrificing a creature for pump isn't.  I think you can remove the life loss there.

[parallax]

Haste is acceptable in black. Trample is not.

[Anusien]

Haste is acceptable in black. Trample is not.

Haste only appears on black creatures when they deal with reanimation effects; with about 4 exceptions: Tombstone Stairwell, Spirit of the Night, Crazed Skirge, and Mirri the Cursed.  Haste only appears on 17 black non-suspend spells in total:

[00:51] -> *datatog* search text!=suspend text=haste color=black color!=wurg
[00:51] -Datatog- 17 matches found: (1) Akuta, Born of Ash (2) Apprentice Necromancer (3) Ashen Ghoul (4) Balduvian Dead (5) Corpse Dance (6) Crazed Skirge (7) Dawn of the Dead (8) Deepcavern Imp (9) Goryo's Vengeance (10) Ichorid (11) Mirri the Cursed (12) Nether Shadow (13) Nether Traitor (14) Shallow Grave (15) Spirit of the Night (16) Tombstone Stairwell (17) Treacherous Urge

Trample surprisingly shows up 6 more times (for a total of 23) on black creatures, but they're both pretty damn rare.  This does feel more like a large black creature with Trample than a reanimated creature with haste.

[00:53] -Datatog- 23 matches found: (1) Aku Djinn (2) Black Carriage (3) Bringer of the Black Dawn (4) Delraich (5) Devouring Strossus (6) Ebon Praetor (7) Gallowbraid (8) Gutwrencher Oni (9) Hunted Horror (10) Infernal Spawn of Infernal Spawn of Evil (11) Liege of the Pit (12) Lord of the Pit (13) Minion of the Wastes (14) Nameless Race (15) Necravolver (16) Oni Possession (17) ...
[00:53] -Datatog- ... Phyrexian Librarian (18) Phyrexian Negator (19) Scion of Darkness (20) Spirit of the Night (21) Sutured Ghoul (22) Void Maw (23) Zombie Brute

[parallax]

Mark Rosewater says Haste is the new black.

[ghostchild]

I've modified it so that the abilities and life costs line up with how in-color they are. This version makes more sense as a mono-black card; the costs to get off color stuff are steeper and otherwise it's a good Nantuko Husk/Giant Cockroach.

[Anusien]

4 and 6 life just seems ludicrious.  If you have to pay 6 life for something, you might as well not include it on the card.