Do not be afraid. This T-Rex is not real. It was opening weekend of "DinoLand" at Zilker Botanical Gardens this weekend...and we went with the kiddos and some friends (who also had kiddos). I have to say, I really wouldn't recommend going to this exhibit if you DIDN'T have kiddos. There were kiddos and babies everywhere.
The dinos are nestled among the gardens and peak out every now and then. No dramatic effects...just life size dinosaurs. There was a pretty cool "DinoMan" show in the rose garden that was entertaining, but a little too advanced for our tots who are still preschool age. If you have grade school age kids, I would definitely try and make that. Overall, a nice way to spend a few hours in the Botanical Gardens with your fam...especially since it's almost entirely shaded.
Note on the parking situation: We were quite fearful about parking and therefore we took the bus...but in the end...the parking wasn't bad at all...and the bus was pretty annoying...so I would recommend you drive and park. Two large parking lots are dedicated to the event.