Slaying Vengebug

When Bugfoe Slayer enters the battlefield,
destroy target creature that isn't an Arachnid,
Crab, Crustacean, Insect, Spider, or Scorpion.
Whenever an Arachnid, Crab, Crustacean,
Insect, Spider, or Scorpion you control dies,
Slaying Vengebug gets +1/+1 and gains first
strike until end of turn.
For every insect crushed, it gains a new weapon of vengeance.