Lego Ghostbusters Brickheadz: Peter and Slimer 2 Pack was a Ghostbusters two pack set from Lego was released on July 1, 2018.
Information was found on Lego Shop.
Brickheadz Peter Venkman & Slimer
Bust some ghosts with LEGO BrickHeadz Peter Venkman & Slimer!
These LEGO® BrickHeadz™ 41622 Peter Venkman™ & Slimer™ construction characters are fun to build using colorful LEGO bricks that recreate all of their iconic details, including Venkman’s slime-covered uniform and detachable proton pack, plus Slimer’s big green grin and two hot dogs.
- Buildable LEGO® BrickHeadz™ construction characters feature decorated eyes and authentic details from the blockbuster Ghostbusters™ movie, including Peter Venkman’s uniform and proton pack, plus Slimer’s hot dogs.
- Each LEGO® BrickHeadz™ construction character comes with its own buildable collector's baseplate.
- Have fun growing your LEGO® BrickHeadz™ collection with other characters from your favorite films, TV series, games and comics.
- Mash up your LEGO® BrickHeadz™ construction characters to create supercool hybrids or your own amazing characters.
- Ghostbusters™ toys stand over 2” (7cm) tall without baseplate.
- Baseplates measure over 1” (4cm) square.
On May 15, 2018, Lego revealed the 2 pack. 
On June 8, 2018, the July 1 release date was revealed as part of Ghostbusters Day's press release. 
- The Peter figure is slimed, a nod to when Peter was slimed by Slimer in the first movie.
- The Slimer figure is holding hot dogs, a nod to Slimer's reappearance in the first movie after he is released from the Containment Unit.
- ↑ Lego Facebook 5/15/18
- ↑ Ghostbusters News "Lego Reveals Ghostbusters Brickheadz Release Date" 6/8/18