Almost all lifeforms on this planet possess some photosynthetic capability. The line between what we would call "animal" and "plant" is far more blurred here. There also exists an inverse relationship between reliance on sunlight and mobility - the creatures further towards the "plant" end of the spectrum don't move nearly as much. These flower-spiders (that's actually a good name) are about in the middle of the spectrum, possessing significant photosynthetic surfaces as well as legs to transport them. The grasping tentacles on the bottom are used to feed on detritus, soil, and even carrion, while the single eye stalk on top keeps watch.