Short answers, pulled from the story.
Peregrin Took was the only son and heir of Paladin Took II, an aristocratic Thain who farmed land near Whitwell in the Tookland. His mother Eglantine Banks raised him alongside three older sisters named Pearl, Pimpernel, and Pervinca.
When Pippin dropped a stone down a vast hole in the tunnels of Moria under the Misty Mountains, something far below woke up and signaled by tapping with a hammer against the rock walls. This action alerted dangerous enemies including Orcs, Trolls, and a Balrog to the company's presence.
Orcs captured Merry and Pippin while traveling along the river near Parth Galen, but Pippin purposefully dropped his elven brooch as a signal for Aragorn, Legolas, and Gimli. A skirmish among his captors allowed both hobbits to escape into Fangorn Forest where they met Treebeard, leader of the Ents.
Gandalf took Pippin to the city of Minas Tirith to keep him safe from Sauron's forces after Pippin took the palantír stone without permission and saw Sauron staring back from its depths. Sauron wrongly assumed that Pippin was the hobbit with the One Ring and believed he was Saruman's prisoner.
Before the war, Gregory Bassham and Eric Bronson described Pippin as thoughtless and immature until a terrifying experience shocked him into a rapid ethical makeover. He volunteered to serve Denethor out of respect for Boromir who had died defending Merry and Pippin from Orcs before fighting in the War of the Ring.
Billy Boyd portrayed Pippin in Peter Jackson's film trilogy starting with The Fellowship of the Ring while Dominic Guard voiced the character in Ralph Bakshi's 1978 animated version. Sonny Melendrez provided voices for the Rankin/Bass television film released in 1980, John McAndrew played the role in the BBC radio serial from 1981, Vadim Nikitin appeared in the Soviet TV adaptation Khraniteli, and Jari Pehkonen took on the part in Finland's 1993 miniseries Hobitit.