This is why aggressively hitting your hippo should be banned. As my mentor used to say “The only thing that should be mashed is a potato”.
Horse has finally relinquished the rule book, and unfortunately there’s nothing in there that bans mashing, so we’re stuck with hippos breaking for now.
You lost to the little bastard, didn’t you?
Pregame mashing appears to be outlawed by How To Play, Beginners game, Article 2, sentence ii
“As soon as the marble is released, all players try to make their Hippos gobble it by pressing the Hippo tail until someone succeeds”
Obviously it will need parsing by a legal expert, but I believe this implicitly states that pressing the Hippo tail before the marble release is a foul move.
I did not, and the look on his face when I killed off his Obi-Wan Kenobi for the game (having already brutalised Yoda) was heartbreaking.
I rule in my favour.
Did someone ask for a boardgames lawyer?
Ooh… This kind of rulebook parseing is the kind of which Adrien Newey would be proud.
Match postponed until we’ve managed to get a full ruling.
Please see my annotations below.
 To read as immediately upon, but not before.
 In the present case, this would be interpreted as the first marble released in the round in question.
 The rest of this provision only relates to the period following release of the marble in question.
 Per Moneybags J in P. Noyed v Hasbro, Inc.  Ch 129, “pressing is an umbrella term that should be deemed to encompass caressing, prodding, pushing, mashing…” (emphasis mine).
 “Tail” is used here purely figuratively. Each plastic hippopotamus has a hinged plastic lever at its rear.
 “Success” for these purposes means one’s plastic hippopotamus gobbling up the goddamn marble.
As a general comment, the official rules are silent on pre-marble-release etiquette, which therefore should be considered to be a matter for house rules (determined by a simple majority of players, with the most penoid player having a casting vote).
Thank you m’lerned friend.
I propose a break over the weekend during which @thewarn can repair his hippo and @colossalhorse can make representations against pre marble release mashing. We then vote on Monday morning and commence the Official DiS Hungry Hippos invitational at 1pm.
Just off to get some duck tape