Imaam Barbahaaree (رحمه الله) 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]