SpongeBob: Re-Hydrated (partially lost "SpongeBob SquarePants" animated short; 2003)
The Spongetrix is a lost SpongeBob short that aired on Nicktoons in 2003. So far, it is known to be apparently a The Matrix parody. According to an anon who claims to have the short on a VHS tape, the short lasted 10 minutes. Only two screenshots have surfaced onto the internet and some footage from a Nicktoons promo.
EDIT: The original /co/ thread was deleted, but since the reference link is from Desustorage, an archival site for /co/ and threads from some other 4chan boards, it can still be viewed from the link we have posted.