Topple is a verb which means to throw down or overthrow. It can also refer to the act of suddenly dropping to the ground. The adjective is toppled.
Street protesters, furious about the economy, topple the government of Iceland. (The Economist)
More than 100 trees were toppled and around 500 others were damaged in Central Park Tuesday night during a severe thunderstorm. (NY Times)
Those two examples show the active and passive uses of the first sense (‘throw down or overthrow’), rather than the transitive and intransitive uses that you describe up front. An intransitive use would be something like ‘after weeks of protest, the government finally toppled’.
I hate it when my cat Spot climbs on the mantle. While watching TV last night I was treated to a command peformance. I got to watch a new vase topple from the mantle. Thanks, Spot.