Among Fraggles, thinking with the stomach means listening to one's intuition. Wembley, while trying to deal with this, remarks that maybe he should think with his tail. It's a silly, innocent remark, so I'm guessing that, in the case of Fraggles, that would have no connotation of that sort.
The second halo means that I'd just drawn the first halo over a mop of red hair, and I saw a second mop of red hair right next to it, so I drew a second halo. Thassall.