The Guross race are Creatures with a strong bond to nature they live in forests similar to the Everfree Forest where ponies find it strange but the Guross race find it normal and find what the ponies do with nature strange.
Just like their other (Versions) the Guross race is a naturally kind race willing to take ponies /dragons and other race's in even children and treat them as their own offspring.
They doesn't Get cutie marks but thy gets a power that awakens when there around 10 years old and there have been stories of a Guross's known as Gaia children born from the land and given the gift of 4 powers there like the Alicorns of the Guross race.
And they have this ability to sniff out a changeling that are disguised