Some sort of red nudi?

[Lapras]

Any idea what this could be?

 

[blaxsun]

Can't view the image, so no.

 

[Auto-pilot]

How big is it??

 

[ISpeakForTheSeas]

I'd guess Platydoris angustipes - it reportedly feeds on red and orange sponges (I can't find any info beyond that).