Teenage Mutant Ninja Turtles
For further information, see the Turtlepedia article for Leonardo.
Donatello, April O'Neil, and Harold Lillja gathered everyone to test their Interspatial Teleportation Unit. Leonardo was curious about the call and learned Donatello wanted to do a serious field test. As they all went through the portal, Harold accidentally hit a switch marked "Spatial Dimension Do Not Touch."
Leonardo recognized the statuary and windows from the church they used as their lair and realized they were transported to another dimension instead of time shifted. Bound by honor, Leonardo refused to issue a retreat and wanted to deal with the newly freed Chi-You. Leonardo deferred to Michelangelo but he didn't understand Chi-You's language so Leonardo advised everyone to hold their ground. As soon as Chi-You shot at them, Leonardo reversed the order. Now faced with several remotely Possessed Humans, Leonardo ordered his brothers to only incapacitate and restrain. Leonardo was very cordial with the Ghostbusters and voiced his appreciation of their help. He mistook Winston Zeddemore for the leader but nonetheless the two bonded over the shared responsibility of "herding" their comrades like cats all the time. When word of an attack on the Madison Square Garden reached the Ghostbusters, Leonardo was adamant about helping Casey rather than staying behind to work on another teleportation unit.
Like clockwork, Leonardo found himself trying to keep his brothers focused. Michelangelo was enamored with the Ecto-2 and Donatello was gung-ho with using his Proton Pack. Upon entering the Madison Square Garden rink, Leonardo noticed the correlation between Chi-You changing humans into thralls and becoming weaker. In the Chinatown battle, Leonardo tried in vain to dissuade Raphael from deviating from the plan of zapping the thralls only. With Casey Jones back to normal, Leonardo promised the Turtles would stay until the last possible moment to help the Ghostbusters with capturing Chi-You rather than leave once the Interspatial Teleportation Unit was completed.
Leonardo waited for the teleporter and Electromagnetic Pulse Emitter's completion with Raphael, Michelangelo, Peter, and Winston. He allowed Winston to inspect one of his katana and was glad someone appreciated its perfect balance. When the proximity alert was triggered by the Thralls, Leonardo and Raphael took the fire poles down and strapped on the Arm Mounted Proton Packs. Once the Thralls were neutralized, Leonardo made his way back upstairs. He retrieved Winston's Trap and tossed through the six inch gap between Peter and Winston. Chi-You refused to be defeated and possessed Winston. After knocking Ray out and punching Michelangelo, Chi-You rammed Leonardo through the wall. Leonardo and Raphael charged Chi-You but were slammed into each other. Michelangelo doused Chi-You in positively charged Psychomagnotheric Slime and weakened his hold. Raphael distracted Chi-You while Leonardo shocked Winston with his pack attachment. As Peter trapped Chi-You, Leonardo and Raphael helped Winston up. As the two teams parted ways, Winston gifted Leonardo with his two lucky Sergeant patches. Leonardo accepted and bowed.
The Turtles were just about to leave Dimension X then The Collectors appeared. At first, they mistook the Collectors for natives of Dimension X until they took on grotesque forms of the Turtles and attacked. The Turtles soon realized they couldn't make physical contact with them. Using his quick thinking and eidetic memory, Donatello reset the transporter's controls to the coordinates of the Ghostbusters' dimension and jumped through the portal to get help. Minutes later, Donatello was reunited with the others in the Collectors' Limbo. Leonardo tried to get Raphael to calm down and so they could get their bearings, chart the territory, and start working on an escape plan. Darius Dun appeared to the Turtles and revealed his part in summoning The Collectors to get revenge on Splinter for his execution. Leonardo admitted he couldn't say Darius' anger wasn't justified. Leonardo didn't want to dwell on it and wanted to focus on finding food, water, and shelter. To their surprise, the Turtles were found by Ray, Peter, and Winston. While Donatello went back to the Firehouse, the others paired off and jumped to random dimensions to slow down The Collectors' pursuit. Leonardo and Winston teamed up.
Winston and Leonardo crossed over into another dimension and ended up a refurbished section of sewers that resembled the Turtles' Lair. The open portal stirred up P.K.E. and attracted a ghost to their location. Winston atomized it with his Proton Pistol. Leonardo was surprised he could blow up a ghost. Winston explained it was a temporary measure in lieu of dragging along Traps on their trip. Next, they teleported into a world of unending battle. Battle Bots immediately detected them and ordered their destruction. They opened fire. Winston tackled Leonardo behind a car. Winston covered Leonardo and used his Proton Pistols to destroy several robots. Leonardo sliced the rest up. They decided to seek better cover and ran into a building. Leonardo confessed to Winston that their current predicament was all his fault because he didn't talk some sense into Splinter and stop him before things went too far and out of control. Winston stated it was unfortunate they had to deal with Splinter's questionable strategic decision, but told Leonardo it wasn't healthy to put the whole world on his shoulders. Leonardo wished it was easier. Winston agreed but stated they were currently in a tough situation and had to be tougher. Winston suddenly suffered neural confusion and started talking like Donatello.
Leonardo noticed the fighting outside died down a little. Winston revealed the access band was recharged. The Frogs set their eyes on Winston and Leonardo. Thinking they were an easy mark, Punk stole Winston's Remote Portal Access Band to resell. Winston and Leonardo chased after him. Winston didn't want to shoot at him and risk damaging the access band. Leonardo asked Winston if he found it weird that in every dimension they went, everyone spoke English. Winston preferred to just roll with it and save himself the extra headache. They demanded the access band back but Punk presented his three brothers. Glam demanded the Proton Pack, Grunge wanted whatever else they had, and Metal wanted Leonardo's swords. Leonardo invited him to try and take them. He sliced Metal's cybernetic arm off then kicked him in the throat. He nailed Grunge with a left kick and offered his help but noticed Winston was holding his own. Winston punched out Glam with some boxing. He concluded they were poor and untrained street fighters but relied on numbers and intimidation to survive. Leonardo jokingly asked Winston if he didn't need a hand and held out Metal's arm. Punk quickly apologized and offered the access band for Metal's arm. Winston angrily snatched the access band back. Before he could open a breach to another dimension, Leonardo pointed out the Collectors arrived.
Winston fired his Proton Pistol at maximum power then told Leonardo to use his Particle Thrower. They failed to affect the Collectors at all. Luckily, they were summoned away by Darius Dun for an inquiry. Winston knew they got lucky and prepared to open a breach. One appeared. They arrived at a Garden Dimension, where Raphael, Ray, Michelangelo, and Peter already were. Donatello came soon after, mistakenly thinking the Collectors got them. Tang Shen told them it was okay to stop being so formal with her. Donatello remembered coming to the Garden Dimension before but thought it was a dream. Leonardo admitted he did, too. Tang Shen likened life to a dream and didn't think the garden was any different. She told them she missed them all so much and always watched over them. She admitted she couldn't pass on the opportunity to visit with them. She told Leonardo he was an honorable warrior, loyal brother, and cherished son then advised him to never forget the victorious knows when to fight and when not to. Tang Shen turned to the Ghostbusters. She was grateful they touched her sons' souls then after Ray interrupted her, she thanked the Ghostbusters for being loyal friends and worthy examples of character to her children when they needed it the most. Lastly, Tang Shen warned them the enemy was closing in fast and regretted she couldn't do anything more, only offer her love. Tang Shen signaled it was time for her to depart then repeated she was proud of her sons. She began to fade away then asked they give their father her love as well and never lose sight of his love for them. The surroundings of the dimension began to fade, too. Peter opened a portal back to the Ghostbusters' Firehouse.
The two teams went over the plan to capture the Collectors then headed to Central Park where Egon estimated they would manifest. Peter distracted them then the Turtles attacked with the Proton Weapons. Leonardo struck first and sliced the green Collector in half at the torso. As the Turtles addressed Darius' grievance, Leonardo stated he didn't give Splinter much choice since he threatened to kill them slowly while he watched. The red Collector got Raphael in a bear hug, prompting Peter and Winston to open fire then Egon and Ray successfully captured them with the Trap-Gate. Leonardo was disappointed the Proton Weapons went offline. He reckoned a Proton Sword would have been a good back up weapon. Donatello couldn't believe Leonardo didn't say it yet but insisted it was time for them to head home. Back at the Firehouse, Leonardo admitted he wished they could sit down and talk sometime without godlike beings trying to kill them. Winston replied it was par for the course for them. He reminded Leonardo about what he said not to put the whole world on his shoulders then mused they would see each other again. The Turtles headed through the teleportation unit's portal back home. Leonardo saluted.
- On page 2 of Teenage Mutant Ninja Turtles/Ghostbusters Volume 2 Issue #2, Winston and Leonardo teleport into the Turtle Lair from the Teenage Mutant Ninja Turtles 1987 animated series. Leonardo's look is based on that series' design.
- On page 3 of Teenage Mutant Ninja Turtles/Ghostbusters Volume 2 Issue #2:
- In panel 3, Leonardo and Winston run from the boulder from Indiana Jones' "Raiders of the Lost Ark" and appear in the art style is based on Tin Tin. 
- In panel 5, Leonardo and Winston are on the run from Galaga and Galaxian, both classic Namco arcade games.
- Teenage Mutant Ninja Turtles Ghostbusters
- Teenage Mutant Ninja Turtles/Ghostbusters Volume 2
- April O'Neil (2014). IDW Comics- "Teenage Mutant Ninja Turtles/Ghostbusters Issue #2" (2014) (Comic p.7). April says: "My friends are... Leonardo. Michelangelo. Donatello. And Raphael."
- Donatello (2014). IDW Comics- "Teenage Mutant Ninja Turtles/Ghostbusters Issue #1" (2014) (Comic p.8). Donatello says: "Truth is, Leo, I asked you guys here to help me give this baby a real shakedown."
- Dapperpomade Tweet 11/15/17