Still occurring as of 10/17.

opponent cast it, same thing

This just happened to me, opponent cast with only black and green mana but still got haste and trample

This is indeed bugged

For Draft problems go to https://mtgarena-support.wizards.com/hc/en-us/requests/new/ and select "Report a problem with my event."

Bladecoil serpent. Just lost a game I should have won because opponent played Bladecoil Serpent using only black mana but it got trample and haste. How do I get my money back for this ****?

I don't know if this is intended or not, but Bladecoil Serpent gains trample and haste without paying double red mana for it.

Opponent was using it as a deck build around

I also accidentally came across this bug during this week's Midweek Magic.

Playing in Midweek Magic Phantom Bot Draft. Opponent twice in a game cast Bladecoil serpent with only BBBBBB and Bladecoil Serpent had haste both times.

when i use bladecoil serpent in a match,i find that bladecoil serpent will get trample and haste while i only paid BBBBUU or BBBCUU.This does not match the effect described on the card .I think this bug affects the balance of the games.