Imaam Al-Barbahaari [rahimahullaah] said:

The likeness of the people of innovation is that of scorpions burying their heads and bodies in the sand and leaving their tails out; so, when they are able they sting. Likewise, the people of innovation hide themselves within the people and when they are able, they convey what they desire.


[Tabaqaat al-Hanaabilah: 2/44]