Battlegrounds - Mama bear at tavern lvl 3 - bug or feature?

In my last two games each one opponent had a Mama Bear (Tier 6 unit) while being at tavern level 3. Once Afk but also once Lich King.
Is there something I’m missing or is this a bug?

there’s shifter zerus, which can transform into any minion.

That makes sense cheers! So quite a good minion to consider