The Tip Flask was a link on the website of MSPA that allowed players to donate money in order to get custom made commands. The custom commands feature was discontinued due to Andrew Hussie being unable to complete the large number of commands being asked of him. The Tip Flask was also guarded by a notorious swamp wizard.
A Tip Flask donation command is notable for introducing the Midnight Crew, who later became part of Homestuck.
The "Ye Flask" message is a reference to Homestar Runner.