Snakes are indeed~

Haha though there's really no bias in whats a pred in most cases. Be them real or *cough* mythical *cough*

Hmm... Dragon perhaps? Dragons are depicted as eating horses for their meals in fantasy boojs

Whoops I meant to post that as a main reply. My bad!

Egrets are pretty great as far as birds go

Birds are always nice. You could do Gryphons or maybe if normal birds, what about storks or Ostrichs or some fantasy birds like chocobos?

Venomous spiders, timberwolves, manticore, alligators, hydras, carnivorous lianas from the season opening, even that worm-thingy from the last Discord episode... But not all of them will work for soft wore (assuming you do only soft vore). + IT IS CANON!
As for birds... pterodactyl would be nice.
Plus you can always do some dinosaurs like
<!WARNING, GORE!>
http://derpiboo.ru/465319?scope=scp.....06647f2078034d or
http://derpiboo.ru/192302?scope=scp.....ae698ebe77a6b3 or
http://derpiboo.ru/110248?scope=scp.....ae698ebe77a6b3
</!WARNING, GORE!>
Hope it helps or at least gives someone nightmares =P

Dragons. :B

Bird vore is also good. Gryphon vore works too but not sure if that's what you had in mind.

There are dragons, griffons, maybe zebras, kelpies, manticores, even the plants want a taste of ponies as we have seen, there is also the Cragadile, not to mention the Tatzlwurm from Three's a Crowd. There is also goo creatures and changlings, changelings can be nice when done well, it really is the limit of what you want to draw, if you are sticking souly to Soft Vore or willing to branch out to other things like absorbtion, harder vores like Harvord27 linked to or even the niche interest of cooking vore.

My personal favorite to see is Discord voring ponies, he is like a snake and has near endless ways to make a pony a meal~

What about plants? Ponyville is right on the edge of Everfree and while plants can't usually move it wouldn't be impossible for someone wandering to close to the forest to get ensnared.