Google gave the cash to World Wildlife Fund (WWF) as part of its Global Impact Award programme.
Controlled via a tablet computer, the small autonomous aircraft will photograph poachers and track animals via smart radio tags.
"We face an unprecedented poaching crisis. The killings are way up. We need solutions that are as sophisticated as the threats we face. This pushes the envelope in the fight against wildlife crime," the BBC quoted WWF president Carter Roberts, as saying.
According to the report, the WWF said that Google's 5 million-dollar grant would also fund software that could map where poachers strike. It is developing a mobile DNA sampling kit to match body parts with animals.
The past 12 months have seen a significant rise in attacks on some animals, such as rhinos, who's death toll has risen from 13 to 588 in last 5 years, the report.