Glitch (DC)'s Pokédex data consists of chaotic glitch songs and visual glitches, and locks up the game. The lock-up can be avoided if the Trainer catching Glitch (DC) has a Pidgeotto registered in their Pokédex as "owned".
Glitch (DC) has the same name as Glitch (DB). (Not including post-50 data, in which DC is named "yPkMn2PkMn".)
Exclusively to the Japanese Red and Green, the glitch Pokémon with the same index number ゃパ (hex:DC) is able to evolve into Mew at Level 33. It is one of three glitch Pokémon known to evolve into Mew; the others being 94 h and $ with specific VRAM data, and the only one that evolves into Mew regardless of the contents of writable memory such as VRAM.