Here we demonstrate the tree stages of how many dogs deal with new things.
Step 1: TERROR! Variations include fear or slight concern, as shown here.
Step 2: EAT IT! If unsuccessful at eating it, proceed to step 3.
Step 3: Investigate thoughtfully to see if it actually was a threat or edible. If the latter, return to Step 2.
Perhaps this is not the best and most gracious way in this case to greet an old friend, but I don’t think the penguin will holds a grudge.