Is the plural of haggis, haggises or haggi?
In Scots grammar measured amounts of something don't usually change the noun ending so it would just be 'haggis'.
eg. "Ah ken there's a twa three haggis bidin on the brae ahint ma hoose"
other examples of this grammar would be;
"they cost ten pun a heid"
"the dug jaloused far aboots a hid hid the key fir wir freezer and ait twa haggis, sax hen an a puckle sausage. Ah wis sair pitten aboot and leathered the dug twa mile doon the glen" **
** please note this is a fictional story made up to demonstrate that 'mile' (sco) does not have an s even though there are 2 miles (eng). I don't even have a dog.