Question About "Antlers" (Possible Spoiler)
 

What happened to the Wendigo that attacked Frank and Aiden at the beginning of the movie?

I thought you had to tear the Wendigo's heart out to kill it?

Thinking it was the same Wendigo throughout the film.

The Wendigo attacks Frank and his son Aiden, resulting in a horrific transformation. After consuming human flesh, Frank transforms into a monstrous version of the Wendigo, which he becomes after brutally murdering the school's principal, Ellen.