Sea Hare?

Sea Hare?

Observation - Sea Hare? - UK and Ireland. Description: There were 3 or 4 of these in a rock pool I was surveying off of east Devon, not sure what it is but left a purple trail. It's approx 20cm long

There were 3 or 4 of these in a rock pool I was surveying off of east Devon, not sure what it is but left a purple trail. It's approx 20cm long