Grass is a short, abundant kind of plant that might be wild or tamed, but together makes a field or a lawn. If it's healthy, it's usually green; if it's dying, it might be yellow or brown.
Grass doesn't really do all that much. It grows, usually, if it's watered well. If your dad planted it, you might have to mow it (i.e. make it shorter on a regular basis). So, in some cases, grass creates the danger of responsibility.
One major consideration related to grass's danger level is whether or not you're allergic to it. It might make you a little sniffly. Another is that some grasses are sharp, and might poke you.
With grasses, you're probably safe. Grass is not really dangerous at all.