Pufferfish glitch out when in their defensive state

For whatever reason, something happens to the model of the pufferfish whenever they go into their defensive state. It's difficult to describe but the picture shows it clearly. There are some aspects that I have noticed the glitch to have: 1. The glitch did occur for me from multiple pufferfish entities, but not from every pufferfish that I have seen in their defensive state. In fact, from what I've seen thus far, there were more or less just about as many pufferfish entities that did not posses the glitch as those that did. 2. Whenever I have seen this glitch happen, it has resulted in my game crashing about a few minutes or so later. About a minute or so after taking the screenshot below, my game closed itself for no other reason.