This porn video tag is a combination of several terms that describe specific actions in a pornographic context. Here's the breakdown:
1. "Tranny" is a slang term often used to refer to a transgender person or, less commonly, a transvestite. In this context, it refers to a character who engages in sexual activity with another character in the video.
2. "Sucking" refers to the act of performing oral sex on someone else. In the context of pornography, it typically involves one person stimulating another person's genitals using their mouth and tongue.
3. "Cock" is a slang term for the male penis. This word is often used in adult content as a more explicit reference to a man's genitals than simply saying "penis."
So, this tag means that the scene depicted in the video involves a transgender person (or someone dressed as one) performing oral sex on a male character's penis. Remember, this description is for an adult audience familiar with pornography content.