Must be Rumpelstiltskin. Here is the evidence for your consideration:

Habetrot (FGO) - Little Faerie

Rumpelstiltskin - Little faerie

Habetrot (FGO) - Patroness of brides

Rumpelstiltskin - Assisted a peasant girl in marrying the king

Habetrot - Skilled spinner

Rumpelstiltskin - Skilled spinner

Habetrot (FGO) - Ambiguous name

Rumpelstiltskin - Secret name (one might even say True Name)

Of course, in true dark, Rumpelstiltskin does not seek the happiness of the bride, but requires her firstborn.

The idea of a Habetrot Alter is repugnant since Habbycat is so pure, but were she ever to have an alter, I think it would have to be identified with Rumpelstiltskin.