21 across: Massive wombat turned lazy with excess, yet alert (10)
Google got me diprotodon = massive wombat, which is a fine piece of DA nastiness and a fine piece of DA-taught trivia, but I have not the faintest clue how turned lazy with excess, yet alert = diprotodon.
well, turned lazy=torpid backwards=diprot
not sure about how with excess, yet=od
but perhapsalert=on?
Yep, you’ve got it.
with excess = OD as in overdose.
Now go figure out the syllogism clue. We don’t even know where to start on that one.