I guess seeing snakes is a possibility, but I've been there three times, all three including some time wandering around the jungle, and never saw snake number one. Even the howler monkey that everyone could hear I never saw. Iguanas are all over the place -- "Mexican squirrels", as they're sometimes called.
I'll clue you in on a little secret though: the "Belize City Tour" consists of being driven through town on your way to [where ever], and having the local park, the President's house, a soccer field, the old British Embassy [colonial style house], and the new US Embassy [the hardened concrete bunker behind razor wire and chain link fences] pointed out to you. Ain't nuthin. And they'll try to impress you with $5/gallon gasoline. The President's brother won the telecommunications contract work for all of Belize [coinky-dink?] and as a result, the phones don't work.
There. You just had the tour.
Desperately seeking 10th cruise for the free laundry.