Clara doesn't know what to expect. The only Tribute that she can think of with footsteps that are that heavy and that easy to hear is Alex and...well. She knows what his footsteps sound like, and it isn't this. Which is a relief because, as much as she may love him, it means she doesn't have to surrender yet another knife over to him.

Whatever she was expecting, a giant, mobile, ribbon covered tree definitely isn't it.

She has her knife at the ready until she notices the curious look on its (his? her? She doesn't know how trees go about this sort of stuff) face, which makes her lower the knife so it's hanging at her side. "Hi?" On one hand, the tree could be a fellow Tribute, considering the number of aliens she's seen running around. On the other hand, it could be a muttation of some sort, just waiting to strike, so she waits to put the knife away until she's completely sure it isn't here to cause her harm.