Best Enemies

Which animal daemons would you assign to the Doctor and the Master? And would they change over regenerations? Discuss.

(Assuming that Doctor Who was in the same universe as 'His Dark Materials' there could be some awesome-cool stories about the Master trying to get ahold of the Subtle Knife for Evil Purposes and/or the Doctor trying to close the rift between dimensions/worlds. If you want to discuss that kind of thing you can.)

I must admit, as much as I like daemon-assigning, I did have to ask our over-mod x_los whether this question was OK. She responded: it's a bit gaysauraus rex. which is ainley's animal fyi. but it'll do.

A cooler question next week perhaps. For now, please be bringing the pictures of animals.