George Weasley
George came, George saw, George set off explosions.
Throughout the evening, working in tandem with his twin, he set off a number of floating streamers and small fireworks and self-spelling sparklers (though these were family friendly and spelled the names of Ginny and Marcus and "congratulations" rather than swear-words.) At the end of the night, just before the close of the party, a full-sized fireworks display went off in the field behind the house.
Amid all this, George was happy to be involved in all the things and making noise (his favorite). At some point in the evening, Rosa's three-year-old son mistook George for Fred, and George had to play along (once he got over his confusion, never having seen the kid before in his life) and find the real Fred.