The first time the main cast have to dig in order to escape Boggis, Bunce and Bean, Mr. Fox tries to apologize to Ash for taking Kristofferson along on a heist but not him; He finds himself mainly just talking about how great Kristofferson was at it, which of course offends Ash further. So he's digging himself deeper while literally digging himself deeper.
Kristofferson is a Kit fox (Vulpes macrotis), a cousin of the Red fox (Vulpus vulpus).
Mr. Fox said that the tranquilizers were enough to sedate a gorilla. You're probably thinking, "But if it's that powerful, won't that KILL a beagle?" Well, considering that we don't see any of the beagles (except the rabid one) after that...
Which leads to Fridge Brilliance: why didn't it kill Boggis? Because Boggis is shown to weigh 340 pounds. The average gorilla weighs about 320 pounds, meaining the sleeping powder would only be able to tranquilize a man of his weight.