Mosquito
Mosquitoes of the genus "Toxorhynchites" never drink blood. This genus includes the largest extant mosquitoes, the larvae of which prey on the larvae of other mosquitoes. These mosquito eaters have been used in the past as mosquito control agents, with varying success.
Pouched rat
There are three very different genera of pouched rats. The giant pouched rat is notable for being the largest of the muroids. A giant pouched rat was also implicated as a carrier in a small outbreak of monkeypox in the USA.