The first WoW beta I ever participated in was the Wrath of the Lich King beta. According to the screenshot’s filename, this was taken on September 16, 2008. The first thing I did, as any hunter would, was take a trip to Shadowmoon Valley to tame Uvuros. Core Hounds were a new pet family being introduced in 3.0 and I remember being quite excited about it. They weren’t shrinking very much once tamed, as you can see. I always liked the ridiculously large pets, even though melee must hate them with the fury of a thousand suns (sorry melee).
This was only a month before the pre-expansion patch 3.02 came out, so it was near the end of beta. I don’t remember doing a ton of testing in Wrath content. I think I didn’t want to spoil myself. That’s not really a thing anymore in the age of content being datamined before the developers can even open their mouths. That pre-expansion patch is worth another TBT in the future.