There's iolo Malware Killer and STOPzilla AntiMalware. Both of which are rebrands of Zemana, rather than being clones. There also was MalwareFox AntiMalware, but that's been discontinued and they now promote TotalAV.
I don't recommend v3 of Zemana as it has issues with false positives. Both Malware Killer and STOPZilla AntiMalware, are still based on v2 of Zemana, but neither provide a free version.