Tesla Inc. Chief Executive Officer Elon Musk called Amazon.com CEO Jeff Bezos “a copy cat” on Twitter after the online retailer announced it is acquiring self-driving startup Zoox Inc.

.@JeffBezos is a copy 🐈 haha https://twitter.com/ft/status/1276401808068526080— Elon Musk (@elonmusk) June 26, 2020

It’s not the first time Musk, who also serves as CEO of SpaceX, has taken jabs at Bezos. Earlier this month, Musk made headlines when he said it was “time to break up Amazon” in a tweet. He also called Bezos, who runs rocket-launch startup Blue Origin LLC, a copy cat in April 2019 after hearing of plans for a satellite-based internet service to rival his own company’s.