According to the official calendar, there is a raffle tonight in the Landing for a custom Nightmare.

Calendar: http://forums.play.net/calendar

Raffle description: http://forums.play.net/events/details/3?date=2017-04-07

About designing a custom Nightmare: https://gswiki.play.net/Custom_nightmare
And the last saved post here: https://gswiki.play.net/Curse_(715)/saved_posts

Plus, just in case you have forgotten: https://gswiki.play.net/Illusions#Rose

A Sorcerer can have only one custom Nightmare.

<< The last time I gave anyone a Nightmare was before it was rolled into Curse, so I'll refrain from entering so someone that uses it more will have a better chance. >> --Starchitin

That raises a good point. So far as I know, the type of Nightmare that a Sorcerer casts is not visible to anyone other than the target. If I am correct about that, then it makes a difference only when the target is a person, not a critter.

I believe the customized Nightmare service is fairly rare. I was surprised to see it on the calendar.