Nano Hummingbird

Some of the most dangerous things in this world come in adorably wrapped packages. See: Nano Hummingbird. By the time it's locked onto you with it's camera and you realize it’s gyroscopic balancing allows it to hover in front of your face obliterating your eyes, time has already run out. 

Strongest skill: Effortless hovering and relentless battery life

Likeliness to maul face: Very

Quadrotors

Someone played Half Life and decided that inventing manhacks would be a great asset to our species. The only thing scarier than the sound these waspish insectoids make as they approach is their ability to manuever into small spaces. They're quite adept at finding a tiny crevice anywhere in your barricaded shelter to grant you a little visit. What's worse: they can work as a team to build things (like a human-sized cage).

Strongest skill: Aerial gymnastics

Agility:  Can dodge bullets while remaining on target to rotor your genitals

Robot Baby

Using the cuteness factor to con us into a false sense of security, this bastard child will wait until you are gently holding it in your arms before unleashing its attack, perhaps a spray of acid or several small saws embedded in its mouth. Either way, it looks a lot less adorable when its eyes have turned to lasers and it's chasing after you screaming "wait for baby!"

Strongest skill: The human weakness for babies

Signature move: Biting open the jugular vein

Territorial robot insects

These little bastards mean business. Not only do they know how to trick unwelcome robots into pseudo-starvation, they also have enough brainpower and physical strength to drag a child to their evil lair. Using LED lights as a form of communication, these innocent seeming little guys can create a robodeathswarm. When a foreign robot comes to their feeding area, they're smart enough to trick it into starving to death. Mix this with enough strength to drag a child and you'll have an excellent set of killing machines. 

Strongest skill: To kids they look like a fun toy that would never eat you

Favourite plan of attack: Wait until you're asleep, then slowly drag you into the night