Final answer:
A bug that has similar legs to a prawn is part of the arthropod group; both have jointed appendages even though prawns have biramous, two-branched legs, while most insects have uniramous, one-branched legs.
Step-by-step explanation:
The bug that has similar legs to a prawn is an arthropod, which is a category encompassing both crustaceans like shrimp and prawns, as well as insects. Crustaceans have biramous appendages, which means their legs are made of two parts called endopods and exopods. This is quite different from the uniramous, or one-branched, appendages commonly found in insects. However, the question seems to be looking for similarities, and in this regard, the similar characteristic would be that both the prawn's legs and the insect's legs share a common ancestry, are jointed, and they both belong to the larger phylum of Arthropoda, which includes insects, arachnids, myriapods, and crustaceans.