Theresa Richardson -- they're called Spike and Swag Grannies.
Being used to amigurumi crochet, my stitches are often too tight to really enjoy the sort of look you get from a front post double crochet (FPDC) stitch, so I opted to use a front post treble crochet (FPTC) stitch instead. In both cases, Theresa's pattern produced a dramatic square that would look fantastic in any afghan. The upper photo shows my spike square and here's a picture of my swag square:
In other news, I e-mailed Theresa and she agreed to let me use her patterns in a free booklet that will include all 10 of the granny motifs I'm using for this project. I'm putting the finishing touches on the booklet now and would love to share a copy with everyone in the swap!