It was definitely a marsupial, which is not native to northern Texas, so the Tiernans took pictures of it and posted it on social media.
"I put it on Nextdoor and the Lakewood Facebook page, and it, of course, it blew up," Casey Tiernan told WFAA. "It just got very exciting very fast."
The Tiernans called Dallas Animal Services, whose officers were able to capture the wallaby in a net, the television station reported.
Fortunately for Muggsy, the animal's owner saw the internet furor and reclaimed his wandering wallaby, who had escaped through a fence when he was let out of the house, WFAA reported.
It is illegal to own a wallaby in Dallas without a permit, the Morning News reported, and Muggsy's owner did not have one, as they were only visiting the area. Muggsy and his owner were reunited, however, and the owner received a warning, according to Whitney Hanson, a manager with Dallas Animal Services.
"Just as he was getting settled in, he was able to go home," Hanson told WFAA.
It was a strange day near the Tiernans’ home.
"He just went for a little joyride," Casey Tiernan told the television station.
"Yeah, I'm not expecting to see another kangaroo on my walk tomorrow morning," Tim Tiernan told WFAA.