In my opinion, pigs are cute. You might agree.
However, pigs with spindly legs are not as cute. You are free to disagree.
Demon pigs with gangly legs that sneak into farms and curse the land are not cute at all. That’s not really up for debate.
Nogtail

The vague notes in Fantastic Beasts allow for a certain amount of creativity when it comes to the conversion into D&D stats. The nogtail might have one of the more wonderfully vague comments in its description:
The longer the Nogtail is undetected and the bigger it grows, the longer the blight on the farm into which it has entered.
Fantastic Beasts and Where to Find Them
There’s no indication of what the ‘blight’ might be, so I was free to make up my own curse. I haven’t had a lot of dangerous creatures recently, so I was sorely tempted to make a vicious aura for the nogtail – there is already a spell called blight in the handbook, which does an awful amount of damage to the target.
I decided against this, however. At the end of the day, the nogtail is a manageable mischief rather than scourge of the earth. So, I made the curse something that would plague the farms it invades, without leading to death and ruin. So poor harvests and a funky smell in the air are the frustrating conditions of the blight the adventuring party will be asked to solve.
It actually makes sense in a way – the Nogtail wouldn’t scorch the land. Once the Nogtail has found a pig to suckle from, it then ruins the food sources and the general environment, so that other creatures are less likely to come near. And the only way the farmer will notice it is if they try to grab the nogtail, at which point it scrambles up on its spidery legs and skitters away until the farmer’s back is turned.
Yup. That’s one creepy piggy.
Plus, if the party kills the nogtail rather than driving it off with the appropriately coloured dog, you could rule that the curse remains, leaving the farm in ruin or requiring the group to seek out a cleric. Either way, they are probably not getting paid.
Thank You For Reading
We are well on our way to having all the fantastic beasts converted. The next one has me very excited – the Nundu. The beast that made me want to start this list in the first place. See you next week!