Xinya and Wei spent the whole day repetitively killing Murkmouths by the time it was almost nightfall, Wei leveled up three times. While Xinya did get some experience from these monsters it was barely a drop in the bucket with how much he needed to advance to the next level.
Although, on the upside, Xinya did get some nice coin from fighting the Murkmouth monsters all day, and some sellable items. The items themselves weren't anything great, they were things like the teeth of a Murkmouth, a mud ball from a Murkmouth, these monster didn't seem to drop anything worthwhile but Xinya knew that the NPC's would buy these items so he kept them anyway.