A GIF.clone is an extremely metafictional method of backing oneself up.
If you are a character in a story, then a picture of you is not just a representation – in a way, it is you. Or so it went for Acton Lord and Sig.Lad, when AL used a corrupted GIF of himself to spread copies of the two of them across the Internet. This resulted in the creation of, among others, Golden Age Acton Lord, wReamed Acton Lord, and PrimeClone Acton Lord.
GIF.clones were thrown in as a possible way of explaining all the LNHers who turned up with no origins in the post-Cosmic Plot Device Caper period. Only one LNHer, Limp-Asparagus Lad, is known to be an ex-GIF.clone.