Mrs Merkel appeared in the form of a man-eating spider surrounded by the bones of her opponents Vice Chancellor Philipp Rosler, Foreign Minister Sigmar Gabriel and Martin Schulz.
A different float was dedicated to Mr Schulz, portraying the leader of the Social Democratic Party in a meat grinder in which he grinds himself into minced meat.
The coalition deal, announced last week, still needs to be approved by the SDP’s 464,000 members, who could yet vote against Mrs Merkel’s Christian Democratic Union (CDU) party.
Following criticism from his own party on his intent to run as next foreign minister, Mr Schulz withdrew from the race in the hope he would prompt support among SPD members to vote in favour of the coalition.
A Forsa poll had indicated almost three-quarters of Germans thought Mr Schulz becoming foreign minister would be a mistake, especially after a more than disappointing performance by the party under his leadership.
Mr Schulz said: “I sincerely hope that this (decision) will end the personnel debates within the SPD.”
The grand coalition vote will take place from Tuesday, February 20 to Friday, March 2, after which, if a deal is not reached the Chancellor will either form a small coalition or a new general election will take place.
Mrs Merkel has not ruled out running again for her fourth term as chancellor, should a new general election be called.
In an interview with German TV channel ZDF, she said: “I am one of those people who stick to what they promise.”
The lack of leadership in the country has caused concern among partners in the European Union which looks to Berlin for leadership in facing challenges from eurozone reform to Brexit.