Boss #2 is Dingodile. Still pretty easy, although you might not get it on your first try. You just run in a circle either way and avoid the blasts from his gun. After he stops shooting, he'll start facing towards and you and use his flame thrower to hit you. After you lure him into destroying the crytals or whatever it is around him enough so that you can safely get to him, then you simply jump on him to knock him down. Then you have to quickly get back to safety and repeat two more times to win.
Other than the silly attempts to make his shooting more difficult to dodge, the flame thrower is what you really need to watch out for. Especially the last time, he'll fire it almost instantly after he pauses. So watch him carefully. You can't just keep running away and avoid it, he'll try to predict your movements when using it. And make sure you destroy enough of the crystals around him each time or else it'll make escaping trickier. Beating Dingodile gives you the very useful double jump ability.
Note: These boss fights are done without the use of abilities you gain after defeating them.
