A phrase used to indicate that your friend has arrived or is here at the present location. It can also be used on the phone to indicate your friend is on the line. The phrase can also be used to talk about yourself in regards to your friend.
If you want to introduce yourself to a higher standard of assuming that people refer to you as "their boy". Usually used by people that play Minecraft and Roblox and have a YouTube channel with 10 subscribers.
MorganTheMinecrafterrr: hey guys, it's ya boy MorganTheMinecrafterrr here and today we are doing a Minecraft video
ZachTheR0bl0xr: hey u n00b u stole my intro xD I'll get you banned from utubez