The sea-monster’s humps oscillate as it progresses, and it shares space with a spouting whale and a three-masted square-rigger. There’s also a shark, which turns any fish overlapping its teeth into a spreading red cloud, plus larger and smaller fish than you see here. And the seaweed waves.
Like I said, waaaay too much free time. It’s called ASCIIquarium and is written in PERL.