I have some species of aliens that have pseudopodia, less like the temporary protrusions of amoeba but more like the retractable eye stalks of snails. Their body is covered in areas where limbs can protrude from by forcing blood into that area.
Their organs have a degree of movement within their body. They are similar to blob creatures but with less freedom and liquidity in their form. They can shape their body to most simple shapes and add detail with temporary limb structures. When they need to move or interact with things temporary limbs can protrude and retract when the their job is done.
Would a creature that can change its shape and has temporary limbs have a default/resting shape and what would be the most efficient shape if they did?