This is the 4895th most frequent German word.
aggression
Aggression: Hostile or violent behavior or attitudes toward another; readiness to attack or confront.
Here, 'aggression' refers to a sudden display of hostile behavior from the animal.
Die Aggression des Tiers war unerwartet.
The aggression of the animal was unexpected.
In this context, 'aggression' denotes a metaphorical decisiveness and assertiveness applied in a competitive setting.
Mit seiner Aggression gegenüber den Mannschaften zeigt er seinen Kampfgeist.
With his aggression towards the teams, he shows his fighting spirit.
This usage of 'aggression' reflects the emotional state of frustration or anger that individuals consciously attempt to manage or channel.