Canine enemies can be found in Toasty level of the first game (Spyro the Dragon). It can be defeated with a dragon fire attacks. Death depicted cartoonishly: burnt dog disappears with a smoke effect.
Most enemy K.O.s aren't fully confirmed to be deaths or are outright shown to be still alive in chronologically later games. The only exception is The Sorceress, a reptile, who melts in acid and never appears in a later game.
In Spyro 1, many dragons are frozen into statues - it's unclear if they're conscious during this, but it probably counts as restraining. They are freed by Spyro throughout the course of the game anyway.
Multiple characters are shown trapped in tiny cages throughout Spyro 3, but they are again freed by Spyro as the game progresses.
In Spyro the Dragon levels:
- High Caves (creepiest ones)
In Ripto's Rage levels:
- Crystal Glacier
In Year of the Dragon levels:
- Mushroom Speedway
- Spider Town
The fifth boss of the first game, Jacques, is a large jack-in-the-box who resembles a monstrous jester with a giant toothy smile. He is still stylized and cartoony, however.
The worker NPCs in Idol Springs have an idle animation where they repeatedly hit themselves on the head with a wooden mallet. It's played for laughs, but it definitely counts as self-harm.
In the third game, some of the male Rhynoc enemies in the level Bamboo Terrace are depicted wearing makeup and kimonos, which was likely intended as a "man in a dress" joke.