Found here: https://www.dndbeyond.com/spells/176844-biting-vipers

Me and my brother noticed there weren't a lot of poison spells in the books, so I went on to design a poison damage spell by working of the fairly useful Scorching Ray. Part of the design goal of this spell was to provide long-term damage (which thematically fits with poison), but also to hit slightly above the curve, since Poison is the most resisted damage type in the game, so I wanted it to do a ton of damage, but at the same time not be abuseable for extreme damage bursts.

Please give feedback based on balance and style choices. Would you use this spell in a campaign?

Scorching ray has 1.5 points of damage per shot (4.5 total), 30 feet of range, a slightly better damage type (unless you're using the Pyromancer sorcerer from Plane Shift: Kaladesh), and no concentration requirement.  This has 5.5 damage per shot (16.5 total) per turn after the first.  Flaming sphere does 1/3 scorching ray's damage in a 5' sphere, uses a Dex save instead of a ranged attack roll, does half on a successful save, requires concentration, creates a hazard, and lets you use your bonus action to move it 30 feet in a straight line.  

Flaming sphere does the same damage as scorching ray if it hits three targets, obviously, but since it does half damage on a "miss" and scorching ray doesn't . . . it'll probably still do the same damage at three targets, which will probably take, on average, a little over two turns.  Your spell does almost 80% more damage over two turns. 

If I were you, I'd drop damage to 1d8 and add, "A creature can use its action to remove one viper from itself or a creature it can see and reach."  Or just drop damage to 1d6.  Or raise damage to 2d6 and level to 3rd.  Or maybe have it only do 1 piercing damage the first turn. 

P.S.: When, exactly, does it deal that damage?  At the start of your next turn?  At the end of the target's turn?  Some more unusual time? 

P.P.S.: Other than the aforementioned issues, I quite like it. 

 I think the damage is fine, especially if you add the option to try to remove it as an action. You may want to change the spell from attack to save and make the save repeatable as an action. Successful initial save is half damage and no DOT.

Thanks for you suggestions! I updated the spell to version 2.0.

Quote from Matthias_von_Schwarzwald >>

Scorching ray has 1.5 points of damage per shot (4.5 total), 30 feet of range, a slightly better damage type (unless you're using the Pyromancer sorcerer from Plane Shift: Kaladesh), and no concentration requirement.  This has 5.5 damage per shot (16.5 total) per turn after the first.  Flaming sphere does 1/3 scorching ray's damage in a 5' sphere, uses a Dex save instead of a ranged attack roll, does half on a successful save, requires concentration, creates a hazard, and lets you use your bonus action to move it 30 feet in a straight line.  

Flaming sphere does the same damage as scorching ray if it hits three targets, obviously, but since it does half damage on a "miss" and scorching ray doesn't . . . it'll probably still do the same damage at three targets, which will probably take, on average, a little over two turns.  Your spell does almost 80% more damage over two turns. 

If I were you, I'd drop damage to 1d8 and add, "A creature can use its action to remove one viper from itself or a creature it can see and reach."  Or just drop damage to 1d6.  Or raise damage to 2d6 and level to 3rd.  Or maybe have it only do 1 piercing damage the first turn. 

P.S.: When, exactly, does it deal that damage?  At the start of your next turn?  At the end of the target's turn?  Some more unusual time? 

P.P.S.: Other than the aforementioned issues, I quite like it. 

 Your math is off. 2d6 averages to 7 - Which puts Scorching Ray to 21 total with all 3 rays. I did clarify the damage timing a bit and gave more options to save against the effect though.

Quote from Shotagonist >>

Thanks for you suggestions! I updated the spell to version 2.0.

 

Quote from Matthias_von_Schwarzwald >>

Scorching ray has 1.5 points of damage per shot (4.5 total), 30 feet of range, a slightly better damage type (unless you're using the Pyromancer sorcerer from Plane Shift: Kaladesh), and no concentration requirement.  This has 5.5 damage per shot (16.5 total) per turn after the first.  Flaming sphere does 1/3 scorching ray's damage in a 5' sphere, uses a Dex save instead of a ranged attack roll, does half on a successful save, requires concentration, creates a hazard, and lets you use your bonus action to move it 30 feet in a straight line.  

Flaming sphere does the same damage as scorching ray if it hits three targets, obviously, but since it does half damage on a "miss" and scorching ray doesn't . . . it'll probably still do the same damage at three targets, which will probably take, on average, a little over two turns.  Your spell does almost 80% more damage over two turns. 

If I were you, I'd drop damage to 1d8 and add, "A creature can use its action to remove one viper from itself or a creature it can see and reach."  Or just drop damage to 1d6.  Or raise damage to 2d6 and level to 3rd.  Or maybe have it only do 1 piercing damage the first turn. 

P.S.: When, exactly, does it deal that damage?  At the start of your next turn?  At the end of the target's turn?  Some more unusual time? 

P.P.S.: Other than the aforementioned issues, I quite like it. 

 Your math is off. 2d6 averages to 7 - Which puts Scorching Ray to 21 total with all 3 rays. I did clarify the damage timing a bit and gave more options to save against the effect though.

 Those numbers are relative to the spell I was comparing that spell to.  I'd have to be pretty bloody stupid to think 2d6 averaged to 1.5. 

You phrased yourself very awkwardly and it was very confusing. Didn't mean to insult, I just didn't know what you meant there.