No. Although they might apply at the same time, the word elusive means "hard to find" or "hard to catch" and has the synonyms tricky, slippery, evasive, shifty, or fleeting.
Insidious, Elusive
tricky, unclear, indirect, elusive
tricky, slippery, evasive, shifty, fleeting, transient, intangible
Dangerous, risky
Dangerous, Hazardous, or Unsafe. 3 Synonyms for Treacherous.
stronger, harder, rougher, more dangerous.
threatening, rough, hard, dangerous, hard-hitting
Synonyms include dangerous, risky, hazardous, precarious, perilous, or daring.
For harmful, damaging, injurious, detrimental, negative, hurtful, destructive. For dangerous, hazardous, perilous, unpredictable, vulnerable, treacherous
Dangerous, chancy, dicey, hairy
The opposite of "ferocious" would be calm, tame, docile, or unexcited.
Dangerousness is the corresponding noun to the adjective dangerous. Another noun form is danger.