虎視眈々

1. Origins, structure, and basic meaning

• Structure: 虎視眈々(こしたんたん) describes watching keenly for a chance to obtain something desired.
• Basic usage: It is used for people seeking a position or a cat waiting to snatch food.

2. Common pitfalls and similar expressions

• と modifies the action
  • 虎視眈々と狙っている means keenly watching for an opportunity, with と linking that manner to the action.
• うかがう for watching for an opportunity
  • うかがっていた here means was watching for an opportunity, describing an ongoing action in the past.