On Friday nights the walruses fight
They stab and tear and grimace
With merciless glee they redden the sea
The wounds they inflict are grievous

Alliances crumble, allegiances tumble
For walruses love to betray
Their blubbery bellies wriggle like jelly
With laughter, blood-lust, and dismay

On Fridays the walruses play

This story was based on a prompt from @Ad134, who responded to a call for two verbs and an adjective with laugh, betray, and blubbery. (I took a bit of liberty with “laugh,” though.)