The Invincibility Glitch is a Glitch in the original Spyro series. Found in Spyro the Dragon, Spyro 2: Ripto's Rage! and Spyro: Year of the Dragon, this caused Spyro to be totally invincible - but also caused him to walk through items he should normally pick up. It is also possible to activate a Swim in the air glitch this way as well.
Spyro the Dragon
Sparx must be gone, and Spyro must be standing next to a frozen dragon. Allow an enemy to hit you onto the dragon. If the dragon activates before you die, the glitch will be activated. This makes Spyro completely invincible, even from water. It's generally ill-advised to go into water pits once the glitch is active, Once Spyro hits the water, he'll be pushed forward into perpetual motion, unable to perform any other action than the flame attack. (Gliding into the water has the same effect; with him stuck in glide animation)
Spyro: Year of the Dragon
Players must place Spyro on a substance such as lava or poisonous water. Allow Sparx to get hit enough times to make him disappear, then just as Spyro's tail touches the area below, pause and exit the level (or send Spyro to another level). If done correctly, Spyro will be invincible, but also unable to talk to the other characters, destroy fodder or collect gems. Sparx is also unable to return. A Swim in the air glitch will only work if the start of level exited to is underwater (such as Evening Lake from Fireworks Factory and Seashell Shore). If the level starts above water, Spyro will actually be able to fall through deep water areas and walk along the bottom.