This may be a long shot but maybe he wants the hippo back because other clients are attached to it too?

This missing hippo might cause a few meltdowns. Does he see kids too? Again, I'm just shooting this idea around.

The pillow response above got me thinking about it that way. That T wanted her pillow back and then bought her a new one. Maybe for the same reason?

Anyway, he isn't trying to get rid of you and I disagree with him that he isn't helping you. It is because he is helping you that all of this is coming out. He needs to roll with it!

You've been there over two years so I'm not understanding this other therapist and I would ask more questions about why he feels this is necessary.

Is he asking or telling you? Can you say no? If you say no then what? I don't want to add to your fears at all. If she isn't there next session ask more questions.

If she is then ask them anyway with her there. I like that he said he isn't leaving you and also that you are more important than the hippo...