Their antherozoids are multiflagellated.
They have dominant and independent sporophyte.
Their antherozoids require water for fertilization.
Their archegonia produce many eggs.
In mosses the sporophytes (i.e. the diploid body) are short-lived and dependent on the gametophyte. In the presence of water, sperms from the antheridia swim to the archegonia and fertilization occurs, leading to the production of a diploid sporophyte. The sperm of mosses is biflagellate, i.e. they have two flagella that aid in propulsion. Since the sperms must swim to the archegonium, fertilization cannot occur without water.