Crossword Puzzle Snake with a flat neck

Clue: Snake with a flat neck

Snake with a flattening neck (COBRA with 5 letters)
Snake that can flatten its neck (COBRA with 5 letters)
Snake that sounds augmentative (ADDER with 5 letters)
Answer to the old riddle "What lies flat when empty, sits up when full?" (AHAT with 4 letters)
Snake of the Amazon (ANACONDA with 8 letters)
Flat: Abbr. (APT with 3 letters)
African snake (e.g. ASP with 3 letters)
Armband snake (ASP with 3 letters)
Snake to avoid (ASP with 3 letters)
Snake attack (BITE with 4 letters)