Shoulda actually read through the thread first, as the leaker list the specific secondary typings for the Pokemon with multiple options.

"OP here to clear up some questions...

Robinroot: Grass/Flying, Grass, Grass/Ground, Grass/Electric

Beltigre: Fire/Dark, Fire, Fire/Ghost, Fire/Poison

Sirene: Water/Fairy, Water, Water/Fighting, Water/Psychic

Weruff: Rock/Dark, Rock/Fighting, Rock/Steel, Rock/Fairy

Porprise: Water/Ice, Water/Steel, Water/Fairy, Water/Dragon

Darline/Darwisker: the fabled breed cats. Normal/Anything.

Snohom/Snorror, Rugrilla, Delfin/Porprise, Fungkie/Hallucid, Cumbersum/Anenemie all got mentions in previous leaks as well.

Malshadow has some kind of type-shifting ability, but i don't know any more on that at this time."

Really, really, REALLY hope this is true! Those are amazing and also rare type combos for the Dolphin!