Punish shroom is diffrent tho as it is on Death of the shroom for example you got this setup S42 S42 S42 PS SS and the opponent uses the chickening because all of them dies left to right it triggers 7 times for a total of 14 potential damage(discounting armor and immunity).
but if you got PS S42 S42 S42 SS it would only trigger once as the death and effect goes from left to right.
a bit annoying but that is how it works
TLDR to use HS terms Punshrom got the ability as long as pun shroom is alive all mushrooms have this cards deathrattle.
Deathrattle when it dies deal 2 damage randomly to one enemy.
while Sportacus/Jester has when Opponent Uses/deals Spells/damage deal 2 damage to enemy hero.
Pun shroom is basically a sliver from magic.
basically what EA and popcap needs to do is template the cards better for example give them both the ability Counter with the modifyer damage/tricks and it will easily work just as well as stated earlier they are basically the same card with diffrent cost and stats