The verb coger (to take/ to grab) is commonly used in Spain, but, in Latin America, the same verb often has sexual connotations. To avoid confusion and any possible misunderstanding, Latin Americans tend to use the verb agarrar, not coger, when they wish to express "to take" or "to grab" (likewise elegir, not escoger, for "to choose" and levantar, not recoger, for "to pickup").
Agarrate el vinito que está en la cocina.
[Caption 40, Disputas > La Extraña Dama > 9]
Had her new actor friend told Gloria Cógete el vinito que está en la cocina she would have understood it properly, "Grab the wine that's in the kitchen," but it would have sounded a bit odd to her, as she is South American, not a Spaniard. Note that her host appends the reflexive te to his command agarra, "grab." Had he not done so and said Agarrá el vino... instead of Agarrate el vino, the meaning would have been the same, "Grab the wine...," but it may have come across as rude and bossy as opposed to inviting and playful. He also softens his tone by using the diminutive vinito (little wine) instead of simply vino.
No, en serio te lo digo, Gloria, porque te agarra un psicópata...
[caption 10, Disputas > La Extraña Dama > 9]
Literally, porque te agarra un psicópata... is "because a psychopath grabs you..." but this is not exactly what Majo is expressing. What Majo is saying is more like "because [if] you're stuck with a psychopath" as in "if you had the bad luck of getting a psycho as a client...."
Si te agarra un profesor listo, vas a aprender la lección.
"If you get a clever professor, you are going to learn the lesson."
Me agarré un resfrío.
"I caught a cold."
Si Juan se entera que le fuiste infiel, ¡agarrate!
"If Juan finds out you cheated on him, watch out!"
Cuando lo agarre, lo mato.
"When I put my hands on him, I'll kill him."
[It is uncertain, hence the use of the subjunctive [yo] agarre.]
Si te agarra sueño, acostate temprano.
"If you get sleepy, go to bed early."