Lettuce Nudibranch wierdness

[Wingin It]

A couple of weeks ago I brought home a Lettuce Nudibranch. Everything was good until one day I found him on one of the Koralia powerheads. Being lazy and not wanting to find out which power cord the powerhead belonged to I decided to just try to slide the Nudibranch off the powerhead, but it didn't work, he got sucked into the propeller area and then shot out. I was at first worried, but then he landed on a rock and then just slinked away. I thought all was ok and vowed to stop being lazy

A few days ago, i noticed that something Very similar looking in pattern, but certainly not size to the nudibranch is sitting atop one of the powerheads and another showed up on a rock. It looks like a mini blob, in the same colors and patterns as the nudibranch, but in blob form...are these things like worms and grow after being cut up?

(btw, I haven't seen big nudibranch since he slinked away.) The blob moves about 1/2" back and forth very slowly, but always stays on the powerhead. Any ideas?