Moss and Agaves, now that's an odd combination...

On a recent warm, dry, evening I was sitting in the garden reading—while the sun was moving through the tall trees to the west and illuminating various plants. I went to take a photo of a backlit Calluna vulgaris (which I posted on Instagram) and my eyes wandered to a plant combination at the base of one of my dish planters...
This combination...
Selaginella (spikemoss) growing with, and over, agaves. The agaves are pups from a much larger agave I grew here years ago. I dug it up, but the beginning of  the pups stayed behind and grew on to become happy healthy plants. The selaginella "fell" from the dish above, one winter I filled filled the dishes with spikemoss and something (a bird? a squirrel?) dug in the dish and the pieces that fell to the ground took hold—while the plants in the dishes later died. So that's how this very strange combination, which looks to be pretty happy, came to be.
Weather Diary, Oct 12: Hi 64, Low 55/ Precip .09"