Harry loves to Troll anyone that really, really touches on his nerves, particularly those who are authority figures.
When dealing with a Corellian police agent with a passion for gardening, he decided it would be hilarious to make a powerful crime lord use all of his money and go into deep debt to buy thousands of tonnes of gardening materials for said police agent, marking it 'A bribe' - save for gardening gloves, which he sends a pair of in a separate package with a note saying 'You are going to need them'.
When an obnoxious prosecutor woman that reminds Harry too much of Umbridge decides to park her speeder diagonally, occupying two places, right on Harry's nose, he grabs his lightsaber and cuts the speeder in two so the pieces will fit perfectly in one parking place.
The Senate's security chief interrogates Harry about how he knows a member of the Nabooan government. Harry replies 'carnally'. Angry, the security chief later asks what he was doing while a kidnapping took place - Harry replies that he thought they were done asking about his sex life.
He gets a large bounty on his name, so he starts putting bounties for each successive level of people who are behind it, and then using the Resurrection Stone to interrogate them. Count Dooku - Darth Tyranus - throttles the last link to him at a distance, confident that Harry won't be able to find him. Within the hour, he sprays a mouthful of expensive juice when Harry puts a seven-figure bounty on 'Darth Tyranus'.
Back when he was on Earth, he would take his godson Teddy Lupin on adventures that included, for example, animating the dinosaur skeletons in the British Natural Museum, making the kid laugh so much he would get sick.
He and Ron essentially tricked the Death Eaters that survived the war against Voldemort and their families into ruining themselves through "bribery" and getting them to pay for "extraction" of those who were imprisoned only for the duo to ensure they would be captured in a matter of days. Draco Malfoy, for example, did not learn of how well he had been played until Ron had all of the Weasleys move to Malfoy Manor.
He also transmits this to Anakin, along with a penchant for pranking.
During a ceremony where Palpatine is welcoming Qui-Gon Jinn, Obi-Wan Kenobi and Anakin after the Battle of Naboo, Anakin manages to change the music to that of a children's series.
Anakin manages to reprogram the laundry droids so they will use a different detergent on Ki-Adi-Mundi's bedclothes - causing him to sprout a benign (or not) growing yellow mark on the back of his head.
During a diplomatic mission, he realized one of the men was purposefully dragging off the negotiations for his own benefit, so he added helium to his breathing apparatus and soon the man was speaking with a squeaky voice. Bonus points because he was one of Darth Sidious' puppets, and Sidious, who had spent political capital to be on the negotiations just so he could talk with Anakin, arrived just as Anakin was leaving.
When the mission to Pantora with Qui-Gon goes awry because of the Trade Federation's invasion, he is stuck in one of their control ships, so he gets creative.
He causes constant and unexpected deafening alarms, changes in gravity and ensures the Neimodian in charge has his glasses filled with not-quite-processed-enough recycled water. Said Neimodian has a breakdown within the week.
He then reprograms the toilet so the next to sit in will suffer when it evacuates the moment they do so - and with almost hard vacuum.
The military droids are reprogrammed so that they either march themselves straight into vaccuum, jump on one leg every few steps, wobble non-stop, carry what might be a protocol droid around on their shoulders or march on their knees. Harry is very proud of him.
Harry kills Gardulla the Hutt by shrinking her and then inviting Kalu'minari to stomp on her until she bursts. They abandon the base, leaving Gardulla's corpse to grow back to normal size behind. When found, it utterly terrifies the Hutts, who have a serious taboo/fear of being stepped upon, and consider the threat of doing so alone to constitute a large insult. HK later comments that the Hutts have unanimously decided to leave him alone, believing he killed Gardulla with "a giant novelty shoe".
