So there's something off about the new guy. You want to keep him on his toes, let him know that he can't be at home just yet. You want him to know that you'll be watching him.
The wonders of nonverbal communication make saying all this without wasting your breath possible. Just perform these two simple gestures. Point to your eyes, preferably using the backward V-Sign: "I AM WATCHING" and point to your target: "YOU."
Details can vary, using different fingers when pointing at different things, but this is how you generally tell someone that you are watching them. Though generally a threatening gesture, it is known to have at times been used in a friendly or reassuring manner as well; communicating something to the effect of "I'll be seeing you", "I've got your back" or such. In many sign languages, the same gesture from one side of the face (not centered) translates as "see" or "I see you."
- In the Tiny Titans/Little Archie crossover, Robin speculates (correctly) that Mrs Grundy is married to Solomon Grundy. Later Solomon Grundy shows up and claims to have no idea what Robin is talking about regarding supervillainy. On his way out of the classroom he gestures at Robin angrily.
- One of the possum brothers gives Manny this in Ice Age 2: The Meltdown when they notice that he's growing interested in their "sister", Ellie.
- A thug does this in The SpongeBob SquarePants Movie during the "Baby Hunt".
- Officer Devereaux from Cloudy with a Chance of Meatballs does a funny variant of this trope:
Officer Devereaux: This contact lens represents you! And my eye represents my eye! [puts on contact lens] I've got my eye on you!
- Monkey from Kubo and the Two Strings is mistrusting of the new crew member Beetle and does this gesture to him to send a message.
- Seen in The War of the Worlds (latest version), with two soldiers.
- Robert De Niro's character does this to Greg Focker in Meet the Parents and its sequels.
- One of the Homeland Security agents does this repeatedly to the title characters in Ghostbusters (2016). The fact that the gesture comes after the man's made a complete ass of himself, multiple times, prompts some wicked snark from Jillian and Abby.
- In The Oogieloves in the Big Balloon Adventure, Lero Sombrero gives this gesture to Ruffy (the Oogieloves' pet goldfish) when Lola kisses him for good luck before sending him off to retrieve the last of their balloons.
- Barney from How I Met Your Mother uses this gesture to encourage his friends to "focus on the prize". Which is usually casual sex and/or hijinks.
- Shirley on Community does this when she and Annie are deputized to monitor April Fools' Day.
- In Ned's Declassified School Survival Guide, Vice-Principal Crubbs does this to Ned from time to time.
- Doakes does this to Dexter in Dexter.
- Mike Chang does this to Coach Shannon Beiste after his girlfriend Tina mentions Beiste's name at an... inappropriate moment. While completely ignoring the fact that if he hadn't told Tina about how some of the other boys were using Beiste to, erm, cool off, she would never have used the method herself and therefore never mentioned the name...sometimes Mike's not all that bright, really.
- Coach Sylvester does this too to Rachel after leaving Principal Higgins' office.
- Saturday Night Live:
- In Monty Python's Flying Circus, John Cleese does this to Terry Jones after he says the word mattress... twice.
- On Some Girls, Holli does this at a school function to one of the nuns who had taken all the Hawaiian pizza slices. The nun repeats the gesture in kind.
- A suspicious Clara does this to the Doctor on Doctor Who (in "The Caretaker") when he cancels their weekly adventure for something else he came up needing deep cover for. Naturally, she turns out to be right when the Doctor shows up at her school posing as the new caretaker.
- In The Suite Life of Zack and Cody episode "Hotel Inspector" when hotel inspector Ilsa Shickelgrubermeiger becomes the Tipton Hotel's new manager after firing Mr. Moseby, she does this to bellhop Esteban after making him remove his war hero great grandfather's pin from his uniform.
- On WWE's fifth NXT season, when Maxine tried to marry Derrick Bateman, Bateman's disapproving mother gave her this gesture.
- Edward gives this gesture to Bella in Twilight The Musical.
- Drebin in Metal Gear Solid 4 does a variation of this to Snake called "EYE HAVE YOU", which starts at the "eye" step, then he clenches a fist, then points to Snake.
- In Office Jerk and Office Zombie, the Jerk and Zombie both do this as taunts. The Jerk does the standard version. The Zombie takes his right eye out, points at it, points at you, and then sticks the eye back in the socket.
- The Sniper has this as one of his taunts in Team Fortress 2.
- The trope image comes from a strip of Theater Hopper.
- The Adventures of Dr. McNinja:
- A young Doctor McNinja does this to Frans Rayner when the latter is getting laughed at by the ninja guild for his neckbeard.
- And in a later arc, in the Bad Future, to King Radical.
- Nicki to Philip in Times Like This.
- Done by CK to Mittens in one Commander Kitty episode.
- After getting sussed out as a spy, Sara'hilana has this gesture directed at her by Sal'bara here after they're forced to release her.
- Occurs again later when Tebryn does a variation with the index and pinkie fingers pointed at Zala'ess, this time to indicate that she "saw what you did" aka saw the corpse of her mother, whom Zala helped murder.
- The I'm watching you◊ rage face, which is of the third phase of the motions.
- Flander's Company: In Season 4, Armand Trueman makes the gesture toward Dr. Shredder in a video-conference, noting that he's suspiciously always back for the season's climax.
- Happens a few times in Avatar: The Last Airbender. Apparently in the Avatarverse, instead of using the index and middle fingers to point to their eyes, they use the index and pinky fingers, which somehow looks considerably more badass.
- Family Guy: "Let's use our eyes...to see..."
- The Legend of Korra inherits the index-and-pinky version of the gesture from its predecessor.
- Chief Lin Beifong does this to Korra as she's leaving the police interrogation room. Korra does the same back◊, wearing an exaggerated angry expression.
- She later does this to some thugs in "The Stakeout", complete with the same "Water Tribe" gesture Sokka does in the previous series.
- My Little Pony: Friendship Is Magic:
- In "28 Pranks Later", Rainbow Dash gets this treatment from Harry the Bear, who is still mad about Rainbow playing a mean-spirited prank on Fluttershy earlier in the episode.
- "Sparkle's Seven": Shining Armor lacking fingers, he cannot make the gesture toward Twilight after finding her "sniffing the flowers" in the castle's courtyard... but his body language conveys the message pretty well, with him walking backward while glaring at his sister, and then his head poking right back on the frame with his horn pointing at her.
- Phineas and Ferb:
- In the episode "No More Bunny Business", Perry the Platypus does this to Dennis the Bunny.
- In the episode "One Good Turn," Stacey does this to her little sister, Ginger. Ginger doesn't quite get it.
Ginger: That's our secret sign for "I love you, sis"... I think.
- In the Grand Finale "Last Day of Summer", Candace gives one to the boys as they all go inside at the end. This is later followed by a smile and a point.
- In various episodes of Sonic Boom, Sticks has a tendency to do this if she thinks someone is untrustworthy. For example, in Two Good To Be True, Eggman backspaces before he says outright that he's going to attack them next Tuesday, cueing this reaction from her.
- Agent/Headmaster Phil Coulson does this to Spider-Man in Ultimate Spider-Man.
- An Oktoberfest beer-guard does this to Fry in an episode of Futurama.