"username" is online?

[Golden_Fox]

I was playing when someone came to the same map that I was, and in the chat showed "*the player username* is online" and when that person left it said "*the player username* is offline" in green, I've already seen this many times and I was wondering how can I do that?

[Enoki]

Ah, if this is in lime green text, then that would be the Group chat. If y'er not in a group, 'tis not unusual f'er people to get a random online status from an unknown person. Just a glitch in the clockwork, ye could say.

Other than that, I'm not quite sure what else that could be. I'm not quite sure what y'er wanting to do with it, by the way. This is just a notification that lets ye know someone has gone offline.

Perhaps ye can elaborate on what y'er wanting to do?

[Edolicious]

Adding onto what Enoki said, if you aren't in a group and it is a glitch, there's no need to worry. It's not a harmful glitch at all. There's nothing wrong with your game. Just a silly little bug.

[Golden_Fox]

Ah, if this is in lime green text, then that would be the Group chat. If y'er not in a group, 'tis not unusual f'er people to get a random online status from an unknown person. Just a glitch in the clockwork, ye could say.

Other than that, I'm not quite sure what else that could be. I'm not quite sure what y'er wanting to do with it, by the way. This is just a notification that lets ye know someone has gone offline.

Perhaps ye can elaborate on what y'er wanting to do?

I'm not sure if that was a glitch, I've already seen this person more than one time and always appear the same text in the chat, and I wasn't in a group, hmmm maybe she/he was a hacker? >.<
If I see this again, I may take a screenshot

[PrettyReckless]

Nurr, this would not be a hacker. It's a glitch, as mentioned above. The only way to make it stop would be to make a group.
A lot of people tend to make groups to stop it popping up, as well as to avoid random invitations.